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-J4
PRACTICAL TREATISE
DIAGNOSIS, PATHOLOGY, AND TfiEATMENT
DISEASES OE THE HEART.
BY
AUSTIN FLINT, M.D.,
PROFESSOR OP CLINICAL MEDICINE, ETC., IN THE NEW ORLEANS SCHOOL OF MEDICINE ;
VISITING PHYSICIAN TO THE NEW ORLEANS CHARITY HOSPITAL ;
HONORARY MEMBER OF THE MEDICAL SOCIETY OF VIRGINIA, OF THE KENTUCKY STATE MEDICAL SOCIETY,
OF THE MEDICAL SOCIETY OF RHODE ISLAND, OF THE PATHOLOGICAL SOCIETY
OF PHILADELPHIA, ETC.
PHILADELPHIA: BLANCHARD AND LEA.
1859.
Entered according to the Act of Congress, in the year 1859, by
BLANCHARD AND LEA,
in the Office of the Clerk of the District Court of the United States in and for the Eastern District of Pennsylvania.
PniLADELPHIA : COLLINS, PRINTER, 705 JAYXE STREET.
Library
zoo
TO
4
PROFESSORS HENRY MILLER, SAMUEL D. GROSS,
LUNSFORD P. YANDELL, LEWIS ROGERS, BENJAMIN R. PALMER,
BENJAMm SILLIMAiS^ JR., J. LAWRENCE SMITH,
T. G. RICHARDSON,
WITH WHOM
THE AUTHOR WAS FORMERLY ASSOCIATED
■ IN THE
UNIVERSITY OF LOUISVILLE,
V
^ ^Ijig Uolumc
IS RESPECTFULLY DEDICATED.
G241f:9
P 11 E E A C E .
In the preparation of this volume, the aim has been to meet the wants of the medical student and practitioner by the production of a work devoted exclusively to diseases of the heart, and treating concisely, but comprehensively, of these diseases with reference to their diagnosis, pathology and treatment. Such a work, if satis- factorily executed, it is believed, can hardly fail to prove acceptable, in view of the importance of this class of diseases, the progress made in their investigation during the last few years, and the absence of any extended text-book, published in this country, having the same scope and objects, since the appearance of Dr. Hope's treatise twenty years ago. The need of a practical work on diseases of the heart is so apparent, that the present efibrt requires no apology; and if not successful, the fault must be imputed to the performance rather than to the undertaking. The author ventures to hope, in submitting this volume to the profession, that it may be found, in some measure at least, to supply a desideratum, the existence of which must have been felt by many practising phy- sicians, and, more especially, by medical teachers and their pupils.
It will be observed that the arrangement of subjects in this work differs from that generally adopted. As regards the order in which the different diseases are considered, the plan usually pursued may be said to be synthetical, inflammatory affections being taken up first, and afterward the lesions which are, to a considerable extent, results of inflammation. A method which may be distinguished as analytical, has appeared to the author preferable. Pursuing this method, the work commences with the consideration of organic affections. Enlargement of the heart, occurring often consecutively to other lesions, takes precedence. To this subject the first chapter is devoted. Lesions affecting the walls of the heart naturally come next in order. These constitute the subject of the second chapter. Valvular lesions are then considered, occupying two chapters, and
VI PREFACE.
a chapter is devoted to congenital malformations. Several affec- tions which are incidental to diseases of the heart, are treated of in a distinct chapter. Then follow the inflammatory affections, and, afterward, functional disorders of the heart, three chapters being allotted to these classes of disease. Finally, thoracic aneurisms, which claim consideration in connection with diseases of the heart, are made the subject of the concluding chapter.
In writing the book, the end which the author has kept steadily in view is, a fair and full exposition of our present knowledge of the diagnosis, pathology and treatment of diseases of the heart. Eecognizing clinical study as the great source of this knowledge, he has endeavored to make the cases reported by trustworthy observers, together with his own recorded experience, the basis of the work. Having long been in the habit of making records at the bedside, and having given for several years particular attention to diseases of the heart, he has accumulated notes of about two hundred cases of the various cardiac affections. The results of an analysis of these cases have been before him during the composition of the work. As a preliminary step, also, over one hundred fatal cases gathered from different authors, chiefly from tbe works of Hope, Stokes, Andry and Blakiston, were subjected to similar analysis. On the data thus obtained have been based, in a great measure, the statements and opinions which the work contains, endeavoring, however, not to introduce details and statistics to an extent to prove repulsive or fatiguing to the reader. But although it may be claimed in behalf of the work that it is something more than a compilation, not to have studied closely the literature of the subject, would have been an injustice alike to it, and to those by whose labors this department of practical medicine owes its present development. Of the authors to whom acknowledgments are due, the names of Bouillaud, Hope. Stokes, Walshe, Andry, Forget and Bellingham are to be especially mentioned. Eeferences to these and others will frequently occur in the following pages. The author has aimed to prepare a practical treatise, and he has therefore avoided, or dismissed with as much brevity as possible, speculative opinions and mooted questions involving discussions which would occupy space to the disparagement of matters relating more directly to medical practice. It may seem, nevertheless, to some, that the volume is out of proportion to the field of practical medicine to which it is restricted ; but it is hoped there will be no reason to complain of a redundancy either in style or matter, and that the
PREFACE, VU
reader will be led to attribute the size of the book to the progress of knowledge pertaining to diseases of the heart, together with their intrinsic claims on the attention of the student and practi- tioner.
A liberal share of the work is devoted to physical signs. But a just estin:iate of their practical importance will obviate any objection on this score. It is mainly owing to physical exploration that the study of these diseases has been prosecuted within the past few years with such remarkable success. Here, as in other classes of affections, the knowledge to be derived from clinical observation is increased in proportion to improvement in diagnosis, and it is evident that diseases cannot be judiciously treated unless correctly discriminated. The discrimination of diseases is confessedly the portion of our art which involves the most difficulty and calls for the greatest amount of skill. Hence, it is especially under this practical aspect that diseases in general claim careful and extended consideration. This remark, certainly, is not less appli- cable to diseases of the heart than to other nosological divisions. And the diagnosis of cardiac diseases is for the most part based on the physical signs. It is, therefore, by no means solely because these are interesting, but on account of their great practical im- portance, that so much space has been accorded to them in the present treatise. In treating of the physical signs, it was necessary to introduce some matter belonging properly to anatomy and phy- siology, viz., the relations of the heart to the walls of the chest and the adjacent viscera, the movements of the organ, and the normal heart-sounds. With reference to the movements and sounds of the heart, the author has been led by examinations of the healthy chest to conclusions which appear to have important practical bearings. The abnormal modifications of the heart-sounds have hitherto scarcely received sufficient attention. More importance is attached to them as diagnostic signs, and they are considered mo.re fully in this work than in any other on the diseases of the heart with whicb the author is acquainted. As regards the sounds of the heart in health and disease, some original views are introduced, which have entered into a previous publication.'
In thus setting forth, briefly, the plan and objects of the work, the author assumes only to have spared no pains to render it
' On the Clinical Study of the Heart-Sounds in Health and Disease. — Transac- tions of the American Medical Association for 1858.
VUl PREFACE.
acceptable to the profession. All who have engaged in similar undertakings amidst the cares and distractions of active medical practice, will appreciate the diflBculty of the task. But the time and labor which the author has bestowed upon it, will be more than requited by the approval of his medical brethren ; and he is encouraged to hope for this reward by the favor with which his previous contributions to practical medicine have been received.
The author would express his thanks to Prof. John C. Dalton, Jr., for the two illustrations which form the frontispiece, and for other friendly offices ; also, to Dr. Austin W. Nichols, formerly assistant to the chair of clinical medicine in the University of Buffalo, for his valuable assistance in collecting materials for the preparation of the work.
New York, September, 1859.
CONTENTS.
I
CHAPTER I.
ENLARGEMENT OF THE HEART.
Definition and varieties of liypertrophy and dilatation
Normal dimensions and weight of the heart
Enlargement by hypertrophy .....
Concentric hypertrophy .....
Symptoms and pathological effects of hypertrophy Normal situation and anatomical relations of the heart . • Physical signs of hypertrophy obtained by percussion Normal situation and extent of the apex-beat Mechanism of the heart's impulse ....
Altered situation and extent of the apex-beat in enlargement Increased force of the apex-beat and abnormal impulses in hyper trophy .......
Clinical study of the heart-sounds in health
Abnormal modifications of the heart-sounds in hypertrophy
Increased size of the prsecordia and abnormal movements in en
largement as determined by inspection . Increased size of the chest as determined by mensuration Diagnosis of enlargement of the heart and hypertrophy . Summary of the physical signs of enlargement of the heart Summary of the physical signs distinctive of enlargement by hypertrophy ......
Treatment of hypertrophy .....
Enlargement by dilatation ......
Pathological process, etc., involved in the production of dilatation Symptoms and pathological effects of dilatation . Physical signs of dilatation ....
Diagnosis of dilatation .....
Summary of the physical signs distinctive of enlargement by dilatation .......
Treatment of dilatation .....
PAGE
17 19 23 31 33 35 40 45 47 49
50 58 63
67 68 69 70
71
72 77 78 80 82 84
84 85
COXTENTS.
CHAPTER II.
LESIONS, EXCLUSIVE OF ENLARGEMENT, AFFECTING THE WALLS OF
HEART.
THE
Atrophy with diminished bulk of the heart
Fatty growth and degeneration ....
Pathological character and antecedent morbid conditions
Symptoms and pathological effects
Physical signs and diagnosis
Treatment Softening of the heart
Symptoms and pathological effects
Physical signs
Treatment Induration of the heart Cardiac aneurism Rupture of the heart
90
92
94
99
101
106
107
108
110
111
112
115
CHAPTER III.
LESIONS AFFECTING THE VALVES AND ORIFICES OF THE HEART.
Aortic and mitral lesions .......
Symptoms and secondary pathological effects referable to the heart
Pain and palpitation .....
Pulse .......
Turgescence of veins and venous pulsation Symptoms and pathological effects referable to the circulation
Cardiac dropsy .....
Arterial obstruction by fibrinous deposits detached from
the valves or orifices — Embolia
Symptoms and pathological effects referable to the respiratory
system . . - . . . .
Dyspnoja ......
H hemoptysis ......
Pulmonary oedema, etc. ....
Symptoms and pathological effects referable to the nervous system
Apoplexy ......
Sleep and mental condition .... Symptoms and pathological effects referable to the digestive sys tcm and nutrition ......
Portal congestion .....
120 127 133 135 142 147 147
151
154 156 159 160 163 165 167
168 169
CONTENTS.
XI
Hemorrliages .....
Nutrition ......
Symptoms and pathological effects referable to the genito-urinary system .......
Bright's disease .....
Symptoms and pathological effects referable to the countenance and external appearance of the body
PAGE 171 171
172 173
174
CHAPTER lY.
PHYSICAL SIGNS, DIAGNOSIS, AND TREATMENT OF VALVULAR LESIONS.
Endocardial or valvular murmurs ...... 177
Classification of organic murmurs ..... 18.o
Mitral direct or diastolic murmur ..... 186
Mitral regurgitant or systolic murmur .... 188
Aortic direct or systolic murmur ..... 190
Aortic regurgitant or diastolic murmur .... 191
Localization of systolic murmurs ..... 194
Localization of diastolic murmurs ... . . . 197
Recapitulation of points involved in the localization of systolic
and diastolic murmurs ...... 199
Pathological import of organic endocardial murmurs . . 200
Inorganic murmurs ....... 202
Abnormal modifications of the heart-sounds in cases of valvular lesions 206
Diagnostic characters of lesions affecting the mitral, aortic, tricuspid,
and pulmonic valves or orifices ...... 209
Diagnostic characters of mitral lesions .... 210
Diagnostic characters of aortic lesions .... 211
Diagnostic characters of tricuspid lesions .... 213
Diagnostic characters of pulmonic lesions .... 21.5
Treatment of valvular lesions ...... 217
CHAPTER V.
CONGENITAL AHSPLACEMENTS, DEFECTS, AND MALFORMATIONS OF THE
HEART.
Congenital misplacements ....... 231
Deficiency of the pericardium ...... 232
Malformations . . . ... . . . 232
Cyanosis ........ 238
Xll
CONTENTS.
CHAPTER YI.
CERTAIN AFFECTIONS INCIDENTAL TO ORGANIC DISEASES OF THE
HEART.
Formation of clots and fibrinous coagula within the cavities of the heart Polypi of the heart ........
Angina pectoris ........
Enlargement of the thyroid body and prominence of the eyes Reduplication of the heart-sounds ......
PAGE
245 253 2.54 267 274
CHAPTER VII.
INFLAMMATORY AFFECTIONS OF THE HEART — PERICARDITIS.
Acute pericarditis ....
Anatomical characters
Pathological relations and causation Connection with rheumatism Connection with Bright's disease Connection with scurvy, etc.
Symptoms ....
Symptoms referable to the heart Symptoms referable to the circulation Symptoms referable to the respiratory system Symptoms referable to the nervous system
Physical signs ....
Signs furnished by percussion Signs furnished by auscultation Signs furnished by palpation Signs furnished by inspection Signs furnished by mensuration
Summary of the physical signs of acute pericarditi
Diagnosis
Prognosis
Treatment Subacute and chronic pericarditis . Pneumo-pericardium and pneumo-pericarditis Pericardial adhesions
283 283 290 291 292 295 297 298 300 303 305 312 312 316 326 328 329 329 331 334 337 351 357 360
CONTENTS.
XUl
CHAPTER YIII.
INFLAMMATORY AFFECTIONS OF THE HEART — ENDOCARDITIS- MYOCARDITIS.
|
PAGE |
||||
|
Endocarditis ......... 371 |
||||
|
Anatomical characters |
371 |
|||
|
Pathological relations and causation |
377 |
|||
|
Connection with rheumatism |
377 |
|||
|
Connection with Bright's disease |
379 |
|||
|
Artificial production of |
381 |
|||
|
Formation of coagula, etc. |
383 |
|||
|
Symptoms |
• |
384 |
||
|
Physical signs |
385 |
|||
|
Diagnosis |
390 |
|||
|
Prognosis |
392 |
|||
|
Treatment . |
393 |
|||
|
Myocarditis .... |
399 |
CHAPTER IX.
FUNCTIONAL DISORDER OP THE HEART.
|
Varieties of functional disorder |
403 |
||||
|
Pathological relations and causation |
405 |
||||
|
Connection with plethora and ansemia |
405 |
||||
|
Connection with hysteria, etc. |
406 |
||||
|
Connection with dyspepsia . |
408 |
||||
|
Connection with gout |
408 |
||||
|
Symptoms .... |
409 |
||||
|
Physical signs |
410 |
||||
|
Signs furnished by percussion |
410 |
||||
|
Signs furnished by palpation |
411 |
||||
|
Signs furnished by auscultation |
412 |
||||
|
Diagnosis .... |
415 |
||||
|
Prognosis .... |
421 |
||||
|
Treatment . |
422 |
XIV
CONTEXTS.
CHAPTER X.
DISEASES OF THE AORTA — THORACIC ANEURISMS.
Inflammation of the aorta .... Morbid deposit on the surface of the lining membrane Atheroma and calcareous degeneration Dilatation of the aorta Thoracic aneurisms .
Varieties of aneurism
Anatomical relations of thoracic aneurisms
Formation and causes
Terminations •
Symptoms
Dyspnoea Aphonia Dysphagia Lividity, etc. Pulse Pain .
Pai'aplegia and hemiplegia . Physical signs
Signs furnished by palpation Signs furnished by percussion Signs furnished by auscultation Diagnosis .... Treatment ....
PAGE
429 432 432 435 436 437 439 441 442 443 444 445 446 447 447 448 449 450 450 453 454 457 461
DESCRIPTION OF THE PLATE
IN FRONT OF THE TITLE.
Fig. 1 illustrates the relations of the heart to the thoracic parietes. The letters a, b, c, etc., indicate the ribs. The figures 1, 2, 3, etc., mark the inter- costal spaces. The vertical line denotes the median line. The right angled triangle extending over a portion of the surface of the heart, represents the " superficial cardiac region" as delineated on the chest with sufficient accuracy for practical purposes. The cross on the fourth rib shows the situation of the nipple. The relations of the ventricles, auricles, apex of the heart, aorta, and pulmonary artery, to the ribs and intercostal spaces, the median line and the nipple, are accurately indicated.
Fig. 2 illustrates the relations of the heart to the pulmonary organs, liver, and stomach. The quadrangular space in which the heart is uncovered by lung is the " superficial cardiac region," represented more accurately than in Fig. 1. The relative situations of the left lobe of the liver, the stomach, and inferior border of the heart, are correctly represented.
DISEASES OF THE HEART.
CHAPTER I.
ENLARGEMENT OF THE HEART.
Definition and varieties of hypertrophy and dilatation — Normal dimensions and weight of heart — Enlargement by hypertrophy — Concentric hypertrophy — Symptoms and patho- logical effects of hypertrophy — Physical signs and diagnosis of enlargement and hyper- trophy— Situation and anatomical relations of the heart in health — Alterations in degree and extent of dulnesa on percussion in hypertrophy — Altered situation and extent of the apex-beat, and abnormal force of impulse in hypertrophy, as determined by palpation — Mechanism of the heart's impulse — Abnormal modifications of the heart-sounds — Dimi- nished extent and degree of the respiratory murmur and vocal resonance within the prajcordia in hypertrophy, as determined by auscultation — Results of the clinical study of the heart-sounds in health — Enlargement of the prajcordia and abnormal movements in hypertrophy, as determined by inspection — Increased size of the chest, as determined by mensuration — Summary of the physical signs of enlargement of the heart — Summary of the physical signs distinctive of enlargement by hypertrophy — Treatment of hyper- trophy— Enlargement by dilatation — Symptoms and p)athological effects of dilatation — Physical signs and diagnosis of dilatation — Summary of the physical signs distinctive of enlargement by dilatation — Treatment of dilatation.
Enlargement of the heart is a term wbicli embraces aboor- mal increase in the volume of this organ, in its weight, or, as is commonly the case, increase both in weight and volume. Aug mentation of the volume of the heart, and of its weight, gives rise to different forms of enlargement, which, although usually associated, may exist each independently of the other. The heart may exceed the limits of health as regards weight, in consequence of an increased thickness of its walls, the normal bulk being retained. This may and does occur, although, in the vast majority of the cases in which the weight is augmented, the volume exceeds the healthy limits. On the. other hand, the bulk of the heart may be abnormally great, the cavities being enlarged, and the thickness of the walls so far diminished, that the normal weight is retained. This form of
9,
18 ENLARGEMENT OF THE HEART.
enlargement is also of very rare occurrence, the organ generally increasing in weight Avhen its bulk is greater than in health. Abnormal increase of the heart in weight, due to morbid thickness of the walls of the organ, constitutes the condition called hyper- trophy. Abnormal increase of the heart in volume, due to the morbid size of its cavities, constitutes the condition called dilatation. These names, hypertrophy and dilatation, thus denote different forms of enlargement of the heart, presented sometimes separately, but usually together. Each of these two forms of enlargement are subdivided by writers into several varieties, the subdivisions being based on well-marked and important distinctions. Hypertrophy difi'ers in different cases, according to the condition of the cavities, as regards size, associated with it. It exists in some cases without any alteration of the cavities, the latter remaining normal. This variety is called pure or simple hypertrophy. The cavities may be diminished in size below the limits of health. This must be admitted as a variety of hypertrophy, although its existence is denied by some. It has been distinguished as concentric hypertrophy, or hypertrophy with contractioyi. The variety occurring much more frequently than the others, in fact, that which exists in the vast majority of the cases in which the heart is hypertrophied, is characterized by the coexistence of dilatation to a greater or less extent. This variety is called eccentric htjpertrophy, or hypertrophy icith dilatation. The other form of enlargement, viz., dilatation, differs in different cases, according to the condition, as regards thickness, of the walls of the heart. Dilatation exists in some cases, the walls retaining their normal thickness. This is called pure or simple dilatation. It is obvious, however, that, in propor- tion to the dilatation, the heart is hypertrophied, assuming the walls to preserve their normal thickness, inasmuch as the mass of muscular structure and the weight of the organ under these circum- stances must be increased. In other cases in which the capacity of the cavities is increased, the thickness of the walls is diminished. In this variety, the weight of the heart may not exceed, and may even fall below, that of health. This is distinguished as dilatation with attenuated walls, or attenuated dilataiio7i.^ The third variety of dilatation occurs with far greater frequency than either of the other
' In the rare instances in wliicli the walls are so attenuated that the weight of the heart falls below the limits of health, the condition is one of atrophy. There is, however, no practical advantage in constituting this a distinct variety of enlargement.
DIFFERENT FORMS OF ENLARGEMENT. 19
varieties, and is cliaracterized by the coexistence of hypertrophy, well marked, the dilatation, however, being predominant.
These subdivisions, although based on distinctions which are real and important, are somewhat complicated and embarrassing to the student. They are consistent with the different morbid conditions of the heart, as determined by examinations after death ; but they are not accompanied by diagnostic criteria, by means of which they may always be discriminated at the bedside during life. A simpler arrangement is clinically more available, and suffices for all prac- tical purposes. We may distribute all cases of enlargement of the heart into two classes, viz., 1st. Enlargement by hypertrophy; and 2d. Enlargement by dilatation. These classes will include, respect- ively, cases in which the hypertrophy and the dilatation are either simple or predominant. In cases of " enlargement by hypertrophy," the cavities may or may not exceed their normal capacity. Cases in which the cavities are diminished will also fall in this class. If the hypertrophy be neither simple nor concentric^ it is included in this class whenever it is proportionately greater than the coexisting dilatation. The symptoms and signs enable the diagnostician to determine, often with positiveness, the existence of hypertrophy, which is either simple, or predominant over a coexisting dilatation ; but to discriminate between the cases in which the hypertrophy is simple and those in which it predominates over coexisting dilata- tion, is a problem in diagnosis by no means easily solved. So in cases of " enlargement by dilatation," the amount of muscular struc- ture may or may not exceed the limits of health. The diagnostic criteria of predominant dilatation are often sufficiently positive; but it is far less easy to decide whether the dilatation be accom- panied with hypertrophy or attenuation. Moreover, as regards prognosis and treatment, after the existence and degree of enlarge- ment are ascertained, it is enough to determine which form of enlargement predominates, hypertrophy or dilatation. In treating of enlargement of the heart, I shall follow the simple classification just indicated.
As a point of departure for the study of those afiections of the heart which consist of abnormal deviations in size, its normal dimensions and weight are to be considered. The healthy stand- ards in these respects are obtained by measuring and weighing a sufficiently large number of hearts presumed to be devoid of disease. As regards measurements, the diameters and the thickness of the walls are the points which have reference to the afiections to be
20 ENLARGEMENT OF THE HEART.
treated of in this chapter. The dimensions of the orifices and valves will be considered in connection with lesions in this situa- tion. The researches of Bizot and others show that the volume of the heart varies according to sex and age. It is somewhat gredter in the male than in the female, and it increases slowly, but pro- gressively, from infancy to old age. It is to be observed that diametrical measurements after death are liable to be affected by incidental circumstances, by which they are rendered only approxi- matively correct. The degree of contraction varies according to the quantity of blood which the cavities contain at the time of death. Observations show that when death occurs from hemor- rhage and from diseases attended by rapid loss of fluids, the cavities are much diminished, and the volume proportionately small ; while, on the other hand, if the cavities are distended with blood, they are dilated, and the volume increased in proportion. In consequence of these variations, the measurements of the entire organ, made by means of careful percussion and auscultation during life, are as reliable, if not more so, than those made in the dead subject. In Bizot's tables are exhibited the mean measure- ments of the length, breadth, and depth of the heart as a whole, and of the two ventricles, respectively, in the two sexes at different ages. As standards for comparison, with reference to the existence of abnormal enlargement, it is sufficient to take into view the vertical and transverse diameters, the contents of the cavities having been removed. And it suffices to express the normal averages in figures approximating to the exact results obtained by taking the mean of measurements, disregarding fractional amounts, which the student cannot be expected to remember. Moreover, the results obtained by different observers present considerable variation, which, in view of the facts just stated, might be expected. Adopting, as a basis, the measurements by Bizot and others, it is sufficiently exact to say that the average length of the heart, measured from apex to base on its anterior surface, in the male, between the ages of thirty and fifty, is about four inches, being in the female somewhat less ; and that the width, measured at its widest part, in the male, is a small fraction over four inches, being somewhat less in the female.'
' Farther details witli regard to measurements of volume are dispensed with as practically not important in this connection. Bizot's extensive and elaborate researches, which will be again referred to, were published in the Mtmoires de la Soci'jte JUdicah d^ Observation de Paris, 1836. For a summary of his results relating to the above points and others, the reader is referred to Hope on Diseases
NOEMAL DIMENSIONS AND WEIGHT OF THE HEAET. 21
The general remarks just made with reference to the normal volume of the heart, are also applicable to the thickness of the walls ; the thickness is greater, as a rule, in males than in females, and it increases with age. It varies, also, according to the contrac- tion of the heart at the time of death, dependent on the amount of blood contained within the cavities, and other circumstances. Hence, measurements here, as with respect to the diameters, in a col- lection of hearts, furnish results which are only approximations to correctness. Pursuing the same course as in expressing the normal standard of volume, it is approaching near enough to exactness to say that the wall of the left ventricle, at its thickest portion, in middle life, is not far from half an inch in the male, and in the female a fraction less. The thickest part of this ventricle is near its centre. The thickness is less near the base, and still less at the apex. The wall of the right ventricle, at its thickest portion, is a little over one-sixth of an inch, in the male, and in the female somewhat less. The thickest part of this ventricle is near the base, and the thinnest near the apex. The relative thickness of the two ventricles is, thus, in the ratio of 3 to 1. The average thickness of the right auricle is estimated to be about a twelfth of an inch, and of the left auricle somewhat greater.
The average normal dimensions of the heart as a whole, and of different parts of the organ, are important as standards of com- parison by which to estimate abnormal changes. Their importance in this respect, however, is less than might, at first viev/, be ima- gined. The deviations from these standards, which are embraced within the limits of health, are to be taken into account. The range of normal variation, as regards the volume of the heart and thickness of its walls, is considerable. An addition of an inch or more to the vertical and transverse diameters may not be abnormal. So, a proportionate amount of increased thickness of the walls of the ventricles may be within healthy limits. To determine the line of demarcation between normal and abnormal deviations, is more difficult than to ascertain averages. It is not easy to fix a maximum and a minimum, beyond which the condition is always
of the Heart, Am. ed., edited by Pennock ; to the work by Dr. Stokes on Diseases of the Heart and Aorta; and to Bellingham on Diseases of the Heart, Part I., Dub. ed. For results of measurements by Ranking, Gross, and others, Gross's Path. Anat., third edition, and Dunglison's Physiology, eighth edition, may be consulted ; see also Traite Clinique des Maladies du Cmur, par J. Bouillaiid, which contains mea- surements by himself and strictures on the researches of Bizot.
22 ■ EI^'LARGEMEXT OF THE HEART.
morbid. And even were the boundaries definitely fixed, it might still be a matter of doubt in some individual cases in which the limits were not exceeded, whether the condition was not abnormal. Enlargement of the heart sufficient to be of much pathological importance, is generall}'' so well marked that its existence does not admit of doubt. Practically, therefore, the want of precise data for defining rigorously the confines of morbid anatomy, does not lead to serious inconvenience. These remarks are applicable, not only to the dimensions of the heart already considered, but, equally, to the capacity of its cavities and to its weight.
The cavities of the heart are not readily measured. Their capa- city varies, irrespective of intrinsic normal differences, according to the quantity of blood which they contain, and the condition of the muscular walls at the time of death. They are also affected by 'post-mortem changes. The two ventricles and. auricles do not, in health, present any marked disparity in capacity. The right ventricular and auricular cavities are somewhat larger than the left. This is probably in some measure due to the greater dis- tension of the former, in consequence of the larger accumulation of blood at tlie time of death ; but, aside from this circumstance, observations show that some disparity exists. The capacity of the auricles is somewhat greater than that of the ventricles. In order to represent the average size of the cavities, it has been tlie custom to say that each will contain a hen s Q^g of medium size. This homely illustration is sufficiently exact. The right ventricle is estimated to contain about two ounces of liquid, and the left ven- tricle not much over an ounce and a half. Dilatation, when it exists to an extent to constitute a lesion of much importance, and as it is met with in autopsies of subjects dead with cardiac disease, is usually sufficiently well marked to be recognized and its degree determined by the eye.
The average weight of the heart, as determined by weighing a large number presumed to be free from disease, and taking the mean, is not easil}' fixed with precision, because the results in different hands difier considerably, a fact which goes to show that the variations within the limits of health are considerable. For the reasons, however, which were stated with respect to the average size of the organ, mathematical exactness in giving the average weight is not practically important. The range of normal varia- tion is more important to be considered. Bouillaud, from the results of Nteighing the hearts in thirteen subjects, fixed the average
ENLARGEMENT BY HYPERTROPHY. 23
weiglit, between the twenty-fifth and sixtieth years, at from eight to nine ounces. Dr. Clendinning weighed a much larger number, nearly four hundred, all from subjects over puberty, and the mean was about nine ounces.' Dr. John Eeid found the average of eighty-nine male hearts to be a little over 11 ounces, and of fifty- three female hearts a little over nine ounces.^ It is sufficient to say that the average weight is between eight and ten ounces. And it is to be borne in mind that if it be found to exceed this average, or fall below it by one and two ounces, it is by no means to be inferred that the condition is abnormal. The medium weight in the female is somewhat less than in the male. The weight, as well as the dimensions of the heart, also increases progressively up to an advanced period of life.
ENLARGEMENT BY HYPERTROPHY.
Under this title are included not only the rare instances in which the enlargement is due exclusively to increased thickness of the muscular walls, but all cases in which the hypertrophy, although, associated with more or less dilatation, preponderates over the latter. In examining the heart, after laying open the cavities and removing their contents, the predominance of either hypertrophy or dilatation is generally obvious to the eye. The two forms of enlargement are combined, in different cases, in every degree of relative proportion. The question is, which contributes most to the morbid size, increase of the structure, or of the capacity of the cavities. Instances, however, occur in which these two elements of enlargement are about evenly balanced. On measuring and weighing the organ, the excess of weight is greater than the abnor- mal dimensions in proportion as the hypertrophy preponderates. The walls are more solid and resisting; the rounded form of the ventricles is retained when the organ is placed on its posterior surface, not being flattened by the collapse of the ventricular walls. If the increased thickness of the walls of the ventricles be due to true hypertrophy, they present externally, and on section, the ap- pearances of healthy muscular structure. The microscope shows
' Avoirdupois weiglit in all the instances cited. 2 Dunglison's Physiology.
24 ENLAEGEMENT OF THE HEART.
the tissue to be normal. The deposit of fat upon the heart, between the fibres, with fatty degeneration of the latter, in some cases adds to the bulk, and gives rise to abnormal appearances of the surface and muscular substance. This constitutes a species of false hyper- trophy, which affects certain of the symptomatic phenomena refer- able to the heart's action. In true hypertrophy, inasmuch as the size of the muscular fibrillas is not increased, it follows that there takes place an actual hypergenesis of the tissue. The several por- tions of the heart may all participate in the enlargement, or it may be confined to one or more of the anatomical divisions without extending to the whole organ. In the great majority of cases all portions are involved, but they are rarely affected equally ; the enlargement is more marked in some divisions than in others. The different portions may not present the same form of enlarge- ment. Hypertrophy may predominate in one part and dilatation in another. This fact renders it necessary to consider the divisions of the organ separately. Of these divisions the left ventricle is the one most apt to be affected alone, and the enlargement is often relatively more marked here than in other portions, when the whole organ is more or less affected. An effect of enlargement is to alter the form of the organ. The width is increased more than the length. The heart is rendered abnormally broad and globular. The conoidal appearance is less marked than in health, the lower extremity being blunted, and the pointed apex, as it were, absorbed into the ventricle. This is more marked when the enlargement is confined to, or involves the right ventricle. Certain points relating to physical signs are explained by the change which the apex undergoes. The degree of hypertrophy varies greatly in different cases. The thickness of the left ventricle may be increased to an inch, an inch and a half, and even two inches. The walls of the other compartments may, in like manner, be doubled, tripled, and even quadrupled. The vertical and transverse dimensions may be five or six inches, or more. The weight may exceed two, three, four, and even five times the normal avera2:e. The larsrest weiarht among the instances that have come under my personal knowledge is forty ounces.
The pathological process giving rise to true hypertrophy is hyper-nutrition. With few, if any, exceptions, this process is a result of undue exercise of the muscular power of the organ. Pathologicall}' considered, it is difficult to account for the produc- tion of muscular hypertrophy of the heart, except as a consequence
MODE OF PRODUCTION OF HYPERTROPHY. 25
of some anterior abnormal condition whicli has induced, for a con- siderable period, augmented muscular power. The principle is the same as in the familiar examples of voluntary muscles becoming disproportionately developed when inordinately exercised. Clinical observation shows that in the majority of cases of hypertrophy, prior abnormal conditions do exist, which stand in a causative relation to this affection. The practical bearing of this view of the pathology is important. In much the larger proportion of cases of hypertrophy, the anterior causative conditions are obvious, and are seated in the heart itself, or in the large vessels. The affection in these cases may be distinguished as complicated hypertrophy ; cases of uncomplicated hypertrophy being those in which the causa- tive conditions are either not obvious or situated remotely from the heart.'
In complicated hypertrophy the antecedent and co-existing car- diac affections are those which involve over-repletion of the cavities, either in consequence of obstruction to the free passage of the blood through the orifices and vessels, or of regurgitation due to valvular insufficiency. The organ being unduly distended and stimulated by the accumulation of blood, its action becomes unduly forcible; the causes of accumulation being permanent and often progressively increasing, the increased action continues and aug- ments, and hyper-nutrition is the result. The hypertrophy com- mences in that portion of the heart which is most directly affected by the complication, but the several portions sustain to each other, in their anatomical structure and functions, relations so close and reciprocal, that causes which at first are limited to one part, affect ultimately the whole organ. The enlargement, however, prepon- derates in the portion which is first affected. Directing attention with some detail to the mode in which lesions of the valves or orifices and vessels give rise to enlargement, we shall be led to consider the development of the affection in the different anatomical divisions of the heart, respectively, taking them up in the order of their greater relative liability to become hypertrophied. Of the several portions, the left ventricle, as already stated, is oftenest enlarged ; next in liability to enlargement is the left auricle ; next, the right ventricle, and, last, the right auricle.
' In 276 cases of enlargement in whicli hypertrophy predominated, Dr. T. R. Chambers (Decennium Pathologicum, Brit, and For. Med.-Chir. Rev., vol. xii., 1853), found the heart free from valvular disease in 75, leaving 201 cases of com- plicated hypertrophy.
26 EXLARGEMENT OF THE HEART.
The lesions which especially lead to hypertrophy of the left ventricle, are those seated at the aortic orifice. Lesions in this situation may involve, as will be seen hereafter, contraction and consequently obstruction, or iuadequateness of the valves and re- gurgitation of blood from the aorta into the ventricular cavity. Contraction and valvular insufficiency are not infrequently com- bined, causing, at the same time, obstruction and regurgitation. Either of these immediate effects of aortic lesions occasions over- repletion of the ventricle ; hence, undue distension and stimulation, followed by undue force of the ventricular contractions, and, sooner or later, hyper-nutrition, usually accompanied with more or less dilatation. The enlargement due to the effects last mentioned, for a time is limited to the left ventricle. Eventually the other com- partments become enlarged. The right ventricle is affected because each of the two ventricles participates in the action of the other. The two not only contract synchronously, but are in part composed of muscular fibres common to both. Hence, causes which either weaken or increase the force of the contractions of the one, exert, to a greater or less extent, a similar effect on the contractions of the other. Clinical observation shows that with enlargement of one ventricle, the other very rarely retains its normal size. This is a mode by which the enlargement is extended, applicable only to the ventricles. Another mode is more effective than tbis. The accumulation of blood within the cavity of the left ventricle offers an obstacle to the free transmission from the left auricle. The blood in passing from the auricle to the ventricle meets witli an obstruction in the already repleted ventricle. Over-accumulation within the left auricle ensues ; hence occurs, after a time, enlarge- ment of the auricle. This enlargement involves generally more or less thickening of the walls, but dilatation here uniformly pre- dominates over hypertrophy. Enlargement by hypertrophy, in fact, pertains exclusively to the ventricular portions of the heart. Persisting repletion of the left auricle offers an obstacle to the free transmission of blood from the lungs; hence arises congestion of the pulmonary vessels proportionate to the auricular accumulation, the latter being the greater, the more the auricular becomes dilated. Congestion of the pulmonary vessels offers an obstacle to the current propelled by the right ventricle into the pulmonary artery ; hence, undue distension and excitement of the right ventricle, leading ultimately to enlargement of this portion of the heart. Over-accumulation and enlargement of the ri^ht ventricle offer an
MODE OF PRODUCTION OF HYPERTROPHY. 27
obstacle to the passage of the blood from the right auricle into that Tcavity; hence result, at length, dilatation and thickening of the walls of the right auricle. Over-accumulation in this auricle induces congestion of the systemic and portal veins. This conges- tion offers an obstacle to the free passage of blood through the arteries of the larger circuit. Finally, this latter obstacle reacts on the left ventricle and adds to the accumulation in that compart- ment, where commenced the several links in the chain of sequences tending to the enlargement, successively, of all the other portions of the heart. And while the whole organ thus becomes implicated, the causes affecting primarily the left ventricle are more and more operative, giving preponderance to the enlargement of the latter. The enlargement of the left ventricle, and, sequentially, of the re- mainder of the organ, will be, ccetens pa7'{hus, proportionate to the duration and degree of the aortic contraction or insufficiency, or of both combined. Obstruction seated in the aorta either near or at some distance from the heart, such as is incident to aortic aneu- rism, leads to hypertrophy of the left ventricle primarily, and, subsequently, of the other portions. The effect is much more marked if the dilatation of the artery extend to the orifice render- ing the valves inadequate, or if valvular lesions permitting regur- gitation co-exist.
Enlargement commencing: in the left auricle occurs in connection with lesions of frequent occurrence, aifecting the mitral orifice and valves, and involving either contraction or insufficiency, or both these immediate effects. In auricular enlargements, however, as just stated, dilatation predominates over hypertrophy. Mitral ob- struction and regurgitation lead to accumulation in the left auricle, the passage of the blood from the auricle to the ventricle being impeded by the one, and a reversed current from the ventricle to the auricle being incident to the other. Nest follow pulmonary congestion and enlargement of the right ventricle, the same as when these results take place in cases of aortic obstruction and regurgitation. So far as the ventricles are concerned in connection with the mitral lesions mentioned, the right ventricle is first en- larged, and its enlargement often, if not generally, preponderates over that of the left ventricle, unless, as frequently occurs, aortic lesions also exist. The enlargement of the right, however, leads to that of the left ventricle, partly from the community in structure and in part from the ultimate effect on this ventricle of obstructive accumulation successively in the right auricle and systemic veins.
28 ENLARGEMENT OF THE HEART.
Contraction and valvular insufficiency at the pulmonary orifice occasion, primarily, enlargement of the right ventricle, precisely as aortic lesions induce, first, enlargement of the left ventricle. Le- sions at the pulmonary orifice after birth, however, are so rarely met with that, practically, their occasional occurrence may almost be disregarded in diagnosis. In foetal life, contraction at this orifice is not very infrequent. It is the point of departure for many of the congenital malformations of the heart. In these in- stances, the right ventricle is often found enormously hypertrophied.
Lesions at the tricuspid orifice being extremely infrequent, enlargement of the right auricle rarely occurs, except consecutively to an affection of the right ventricle. Over-accumulation in this ventricle involves obstruction and accumulation within the auricle with which it communicates, and the ulterior consequences already mentioned. The remote and incidental eifects of obstruction to the circulation, except as regards the size of the heart, will be con- sidered, in connection with the subject of valvular lesions, in another chapter.
Enlargement of the heart, uncomplicated with other cardiac affections, may be traced in some instances to obstruction at a dis- tance from the centre of the circulation. Pulmonary obstruction, incident to emphysema of the lungs, and occasionally to chronic pleurisy, collapse, and dilated bronchi, leads to cardiac enlargement. In these cases, the point of departure is the right ventricle, and the enlargement of this portion preponderates over that of the other compartments.-' Obstruction in the systemic vessels, occurring inde- pendently of prior disease of the heart, and sufficient in degree and persistence to give rise to enlargement of the heart, is not so easily determinable as pulmonary obstruction. It has been conjectured that in this way Bright's disease of the kidneys may lead to cardiac disease, these affections being not very unfrequently associated. It is, however, a question whether, in such instances, the affection of
' Dr. Gairdner, of Edinburgh, has suggested that enlargement of the heart, inci- dent to emphysema and other affections of the lungs attended with diminution of their substance, may be produced by the dilatation of the chest in inspiration, and that obstruction of the pulmonary vessels plays a subordinate part in the enlarge- ment. The suction force thus exerted of course cannot be made to explain hyper- trophy, but only dilatation, nor can it be considered as acting on the right ventricle to the exclusion of other portions of the heart. Vide art. in Brit, and For. MecL- Chir. Rev., July, 1853, entitled "Considerations on the causes of dilatation of the heart, with an analysis of evidence bearing on the connection of that affection with disease of the lung."
MODE OF PEODUCTION OF HYPERTROPHY, 29
the kidneys bo not consecutive to, and dependent upon, the affec- tion of the heart. The changes which the arteries undergo in the latter part of life, by which their elasticity is impaired and their calibre diminished, are, with much reason, supposed to stand in a causative relation to enlargement of the heart in some cases. These changes, perhaps, in a measure at least, account for the progressively increasing size of the heart, which, according to the researches of Bizot, marks the progress from middle life to old age.
Cases of uncomplicated enlargement, as already stated, are few in comparison with the number of those in which the enlargement is associated with other and anterior cardiac lesions. If from the number of the former are excluded those referable to obstruction situated remotely from the heart, the residue is exceedingly small. Pushing still farther this elimination, and rejecting the cases in which hypertrophy is associated with dilatation, in other words, accepting only cases of simple hypertrophy, their occurrence is so rare that they may be classed among the curiosities of medical experience. The best specimen of simple, uncomplicated hyper- trophy Avhich has come under my observation, was obtained at the autopsy of a young unmarried female, who died after an aboftion had been procured, in the latter part of pregnancy, by a practitioner of homoeopath}^, who was convicted of the crime and sent to the State prison. This female had apparently been well and vigorous until her pregnancy, when she became anasarcous. The kidneys presented evidence of granular degeneration. Death occurred just after delivery, during a convulsion. The heart in this case weighed fourteen and a half ounces ; the thickness of the left ventricle was nearly an inch, and that of the right ventricle a fourth of an inch. jSTone of the cavities appeared to be enlarged. Nothing was developed in the judicial investigation of the case to show that there had existed symptoms referable directly to the cardiac hyper- trophy.
It was formerly supposed that prolonged functional disorder of the heart frequently eventuated in the development of hypertrophy. This opinion, sanctioned by Corvisart, is not sustained by clinical experience. It may be fairly doubted if the palpitation incident to anemia and other inorganic causes be ever competent, in itself, to induce hypertrophy. At first view, this statement may appear inconsistent with the fact that the abnormal growth of the muscular walls of the heart is the consequence of abnormal muscular action of the organ. This inconsistency disappears when it is considered
30 ENLARGEMENT OF THE HEART.
that functional palpitation, even when intense, does not involve that increase of power or strength of muscular action which is incident to the over-accumulation of blood from an impediment to the circulation. Moreover, the increased action from nervous ex- citation is never so constant and persisting as that due to valvular or other lesions which occasion obstruction. In the latter case, hypertrophy is the result of increased action, beginning imper- ceptibly and progressively increasing for many months, and even years.
In leaving this branch of the subject, it should be stated that, although in the immense majority of cases enlargement is referable to obvious lesions either within or without the heart, involving impediment to the circulation, a few instances are on record in •which the organ attained to an enormous size, and no other lesions were discoverable. A case is cited by Jones and Sieveking in which the heart weighed five pounds, the valves being perfectly healthy, and no morbid appearances elsewhere discovered to ac- count for the enlargement. Perhaps the most rational explanation whicb can be given of these cases is that, congenitally, the size of the heart is disproportionate to the capacity of the vascular system. This explanation was given by Laenuec, and is adopted by Eo- kitansky.
The account which has been given of the manner in which the several compartments of the heart become enlarged is applicable, in a measure, to both forms of enlargement, viz., hypertrophy and dila- tation. In the vast majority of the cases of enlargement by hyper- trophy, it is to be borne in mind that the hypertrophy is accom- panied by more or less dilatation. The causes which determine a predominance of dilatation will be more appropriately considered in a subsequent section of this chapter, devoted to the subject of " enlargement by dilatation." The same causes determine the degree of dilatation which accompanies hypertrophy when the latter predominates. In cases of enlargement by hypertrophy, the accompanying dilatation, according to the views of some writers, precedes the hypertrophy. It is more reasonable to suppose the reverse of this, i. e., that the dilatation is consecutive to the hyper- trophy. The first eflect of over-distension and stimulation from an undue accumulation of blood is the increased growth of the muscular walls. In the healthy, vigorous action of the heart, the ventricles, probably in general, contract, so that the endocardial surfaces come into apposition, and the contents of the cavities are
CONCENTRIC HYPERTROPHY. 31
completely expelled.^ Over-repletion of the cavities excites a more forcible ventricular action, which for a time overcomes the obstruc- tion inducing the repletion. Meanwhile, hjper-natrition follows, and hypertrophy is produced. The increased muscular growth for a certain period protects against the occurrence of dilatation. At length, the hypertrophy reaches a limit when it increases slowly, if at all. The causes, however, persist, and perhaps become more and more operative. Dilatation then ensues, and from this period the progressive enlargement is due chiefly to augmentation of the cavities. This view is not only rational, but sustained by facts derived from clinical experience. Observation shows that, as a rule, in proportion to the duration of organic affections of the heart inducing enlargement, dilatation exceeds, relatively, hypertrophy; and, in the great majority of the cases in which death occurs, not from affections incidental to heart disease, but as a termination of the latter, dilatation predominates over hypertrophy. According to this view, hypertrophy becomes an important conservative provision, first, against over-accumulation of blood, and, second, against the more serious form of enlargement, viz., dilatation.
Hypertrophy with diminution of the size of the cavities claims a few words. Under the title of " concentric hypertrophy"^ (first described and so named by Bertin), this was regarded formerly as a morbid condition occurring not very unfrequently. The investi- gations of Cruveilhier and others within the past few years have led some pathologists to reject it entirely as a morbid condition, and, it is generally conceded that, if it ever occurs, the instances are extremely rare. The ventricular cavities, in connection with increased thickness of the walls, are sometimes observed after death to be considerably diminished. This fact is not doubted ; but it is supposed that both the diminished cavities and the thickened walls in such cases are due to an unusual desrree of tonic contraction of the muscular fibres persisting after death. Cruveilhier found this appearance in the bodies of persons who had suffered death by
' That the inner surfaces of the ventricles come into contact, and with conside- rable force, was shown by an appearance presented in a heart contained in my collection. A rough, projecting, calcareous deposit existed on the anterior curtain of the mitral valve. Directly opposite, on the septum, over a space corresponding in size, as well as situation, to this deposit, the endocardium had become thickened and opaque, evidently due to the forcible pressure of the rough, calcareous mass. The ventricle was hypertrophied and dilated.
^ Also called centripetal hypertrophy. (Bouillaiid.)
32 EXLARGEMENT OF THE HEART.
decapitation. It has been observed in other cases after death from hemorrhage, and from diseases accompanied with much loss of fluids. In some instances, the contracted size of the cavities may be made to disappear bj mechanical dilatation with the fingers, and it may disappear spontaneously some time after death, espe- cially if the heart be macerated in water. The coexistence of contracted cavities and morbid thickness of the walls, is deemed inconsistent with the conditions giving rise to hypertrophy, and the mechanism of its production. The tendency of these conditions, in most cases, is, undoubtedly, to dilatation. Yet it is conceivable that causes which have induced hypertrophy without dilatation may cease, and that afterwards the tendency of the hypertrophy is to lessen the ventricular cavities. This is the more intelligible when it is considered that, according to the view which has been presented in the development of hypertrophy and dilatation, the former in point of time takes precedence. Hypertrophy of the left ventricle, with contraction of the cavity, may be accounted for in cases in which there exists either mitral contraction or regurgita- tion. This ventricle, under these circumstances, may become hypertrophied in the manner already considered, while, owing to contraction at the mitral orifice, or regurgitation, the accumulation within its cavity, instead of being sufiicient to occasion distension, for a time, at least, is less than normal, and, therefore, the tendency of the hypertroph}'-, while this state of things continues, may be to contraction rather than dilatation.^ Without discussing the subject, which does not possess much practical importance, the possibility of concentric hypertrophy must be admitted, while it is probable that, in the majority of the cases formerly so considered, the appear- ances after death do not fairly represent either the capacity of the cavities or the thickness of the walls during life. It is to be borne in mind that, in the cases in which unusual tonic contraction of the ventricles is suspected, the thickness of the walls may not be adequate evidence of the existence of hypertrophy. The weight of the heart is the test in such cases. If the weight exceed the limits of health, without reference to the size of the cavities or thickness of the walls, it is to be concluded that hypertrophy exists.
' This view is adrocated by Professor M. Forget, of Strasbourg, Precis TJi^orique et Pratique des Maladies du Caur, etc., 1851, p. 247. Prof. F. contends that ab- normal diminution is liable to occur whenever an obstruction exists, as regards the circulation, at a point behind (en arrihre) the diminished cavity, the tendency to dilatation always existing if the obstruction be situated anteriorly (era avanf).
SYMPTOMS OF HYPERTEOPHY. 33
Symptoms and Pathological Effects of Hypertrophy.
The symptoms of bypertropTiy, in the eases which come uncler the cognizance of the physician, are generally intermingled with, and obscured by, those of the concomitant cardiac or other afiec- tions which have given rise to enlargement. Cases of simple, uncomplicated hypertrophy are so rare that its clinical history can hardly be said to have been established by observation. The symptomatic phenomena which are described as distinctive of it have been determined inferentially rather than by facts observed in well-authenticated cases. Rationally considered, it is clear that the symptoms would be those indicative of abnormal energy or power of the heart. Undue determination of blood to the head might be expected to occasion certain phenomena, such as cepha- lalgia, flushing of the face, throbbing, vertigo, etc. These symptoms have relation to hypertrophy affecting the left ventricle. Assum- ing the absence of aortic obstruction and of mitral regurgitation, the pulse would represent the power of the ventricular contractions by its force, fulness, and incompressibility. Dyspnoea, when, from any cause, the action of the heart is increased, as, for example, after exercise, would denote that the hypertrophy affected the right ventricle. Of the powerful action of the heart the patient would be conscious when his attention was directed to it, and it would be apparent from the movements of parts of the body and the dress. The digestive and assimilative functions would not be expected to offer any marked symptoms of disorder. The muscular strength would not be diminished, nutrition would not be impaired, nor the functions of secretion and excretion interrupted. This is a brief account of a hypothetical case of simple, uncomplicated hyper- trophy, I am unable to give a description based on personal observation, or on an analysis of reported cases. The group of symptoms is not highly distinctive ; the affection would be likely to be overlooked, and, if the hypertrophy were but moderate in degree, the immediate inconveniences would probably not be suffi- cient to lead the patient to seek for medical advice.
Associated with valvular lesions, emphysema, aneurism, and other antecedent and causative affections, the symptoms distinctly refer- able to hypertrophy are few. The cerebral symptoms are attribut- able to obstructed circulation rather than to an abnormal power of the heart. The same remark applies to dyspncea and other
84 ENLARGEMENT OF THE HEART.
pulmonary symptoms. Valvular obstruction and regurgitatiou modify, in a marked degree, the characters of the pulse. In short, that which chiefly possesses significance is the evidence afforded by observation and the consciousness of the patient that the heart habitually acts with undue strength. To this the mind of the patient becomes accustomed, and he often appears unconscious of it, even when it is very marked on a physical examination of the prsecordia. This evidence of hypertrophy lessens in proportion as it is accompanied by dilatation, and finally disappears when the latter predominates.
The pathological effects of hypertrophy are to be disconnected from those of concomitant affections and accompanying dilatation. Thus isolated, it is not easy to impute to it any special or very important pathological effects. It has been supposed that hyper- trophy of the left ventricle sometimes leads to apoplexy and hemi- plegia, due to extravasation of blood or congestion, in consequence of the force with v.'hich the current of blood is propelled into the vessels of the brain. That these cerebral affections occur as effects of disease of the heart is not to be denied, but the cardiac affections which more especially tend to produce them, are those involving obstruction to the return of blood from the head. Moreover, it is to be borne in mind that great hypertrophy of the left ventricle is (generally complicated either with aortic obstruction or regurgita- tion, or both, and that, under these circumstances, the strain upon the coats of the cerebral arteries is not commensurate with the force of the ventricular contractions. Statistical researches show that the occurrence of apoplexy in connection with heart disease, is not proportionate to the degree of hypertrophy,^ Hypertrophy of the right ventricle has also been supposed to give rise to htemoptysis and pulmonary apoplexy. But clinical observation shows that these effects very rarely, if ever, take place, except when (as is often the case) with hypertrophy of the right ven- tricle, is conjoined contraction of the mitral orifice. The latter involves an impediment to the pulmonary circulation more likely to o'ive rise to hemorrhage than the force with which the blood is propelled by the hypertrophied ventricle. Dropsical effusion into the areolar tissue and serous cavities (general dropsy) is a common effect of organic disease of the heart. It is not, however, an efiect
' See Walslie on Diseases of the Luugs and Heart, second edition, for an analysis of cases collected from different authors, the results appearing to show that hyper- trophy has little or no effect iu determining the occurrence of apoplexy.
PHYSICAL SIGNS. 35
attributable to l\ypertrophy. Simple, uncomplicated hypertrophy would be incapable of producing it. When it occurs in connection with cardiac enlargement, it is due to obstruction from valvular disease or from dilatation.
Physical Signs and Diagnosis of Enlargement and Hypertrophy.
The physical sigas of enlargement of the heart are common to both forms, viz., hypertrophy and dilatation. After having con- sidered these signs in the present connection, it will only be neces- sary to refer to them briefly in treating of dilatation. Incidental to their consideration will be noticed the points distinctive of enlarge- ment b}' hypertrophy. The different methods of physical explora- tion contribute evidence of cardiac enlargement. Enumerating them in the order of their relative importance, the methods avail- able in the diagnosis are percussion, palpation, auscultation, inspec- tion and mensuration. The signs obtained by these different methods may be conveniently classified and considered as follows: 1. Ex- tended and increased dulness in the pr^cordia, as determined by percussion. 2. Altered situation and extent of the apex-beat ; im- pulses elsewhere than over the apex of the heart; and abnormal force of impulse, as determined by palpation. 3. Abnormal modifications of the heart-sounds ; diminished extent and degree of the respira- tory murmur and vocal resonance within the prtecordia, as deter- mined by auscultation. 4. Enlargement of the prsecordia and abnormal movements, as determined by inspection. 5. Increased size of the chest, as determined by mensuration.
1 . Extended and increased didness in the prcecordia as determined by
2)ercussion.
It is obvious that the diagnostician must be acquainted with the extent and degree of the prtecordial dulness due to the presence of the heart in health, before he is prepared to appreciate the signs of disease furnished by percussion. With reference to the results of percussion in health, the position of the heart and its anatomical relations to the lungs and the thoracic walls are to be considered.^
The heart is situated between the cartilages of the third and sixth ribs. The upper extremity, or base, is defined with sufficient
' Vide Fig. 1, Frontispiece.
86 ENLARGEMENT OF THE HEART.
precision bj the upper margin of the third rib. The point or apex generally extends to the fifth intercostal space, near the junction of the rib to its cartilage. The organ is situated obliquely within the chest; a line passing through the longitudinal axis would intersect obliquely the clavicle near its acromial extremity. The median line and a vertical line passing through the nipple, are convenient landmarks for indicating the space which the heart occupies trans- versely. The median line divides the heart, leaving about one- third on the right and two-thirds on the left side. The left margin in the male extends to a point just within the nipple which is situated on the fourth rib near the junction of the rib with its car- tilage. The point or apex is about three inches to the left of the median line, and an inch within a vertical line passing through the nipple. The right margin of the organ extends from half an inch to an inch beyond the sternum on the right side. Viewing the several portions of the heart in relation to the median line, on the rioht side are situated the rio;ht auricle and about a third of the right ventricle; on the left of this line are situated two-thirds of the right ventricle and the left auricle.
The relations of the heart to the adjacent organs are important with reference to the signs furnished by percussion and other me- thods of exploration. At the base are the large arteries connected with the ventricles, viz., the aorta and pulmonary artery, which extend upward beneath the sternum, the latter to the level of the upper margin of the second, and the former nearly as high as the first rib. The course of these vessels, and their respective posi- tions relatively to each other, and to the thoracic walls, are of im- portance in regard to certain auscultatory signs, and will be referred to in that connection. The portion of the heart situated on the right of the median line is covered by the right lung.^ The lower border of the organ, to the left of the median line, lies on the diaphragm, which separates it from the left lobe of the liver, and toward the apex from the stomach. Its relations to the stomach are more or less extensive, according to the degree of distension of the hitter organ. The portion of the heart lying to the left of the median line is only partially covered by the left lung; a part is in contact (the pericardium of course intervening) with the thoracic walls. The space on the chest beneath which the heart is un- covered of lung, is called the sui)erjicial cardiac region. The space
' Vide Fig. 2, Frontispiece.
ANATOMICAL RELATIONS OF THE HEART. 87
beyond this region occupied bj the heart, situated beneath the right border of the left lung, is called the deep cardiac.region. These names will often recur, and their import should be understood. The left lung extends downward on the median line to the level of the junction of the fourth costal cartihige with the sternum. From this point the border of the lung diverges, leaving an irregular quadrangular portion of the. heart's surface exposed. This space may be embraced with sufficient precision for practical purposes within a right angled triangle, delineated as follows:^ The oblique line, or hypothenuse, is drawn by connecting a point at the centre of the sternum on a level with the junction of the fourth costal cartilage, with the point wdiere the apex of the heart comes in con- tact with the thoracic walls, usually in the fifth intercostal space, about an inch within a vertical line passing through the nipple, or about three inches to the left of the median line. The median line extending from the same point on the sternum, and a line extend- ing transversely from the point of apex-beat to meet the median line, will form the two other sides of the triangle. The superficial cardiac region is thus bounded on two of its sides by lung, and on the greater part of one side, viz., the lower, by the liver and sto- mach, with the diaphragm intervening. The limits to which the deep cardiac region extends beyond those of the superficial cardiac region, have been already defined in giving the boundaries of the space which the heart occupies within the chest.
This account of the situation and anatomical relations of the heart, based on examinations of the dead subject, is sufficiently exact for practical purposes ; but in the living body, it is to- be borne in mind, the position of the organ relatively to the thoracic parietes and the adjacent organs varies within certain limitations, not only in different persons, but in the same person at different times. The size of the organ is variable, owing to a greater or less accumulation of blood in its cavities, more especially in the auricles. The whole organ is movable to some extent. The base is comparatively fixed, but the apex moves freely in a lateral direction, and varies its position in different postures of the body. The superficial cardiac region is larger or smaller according to differences in different persons as regards the volume of the left lung and the conformation of the chest. It is small in robust persons with deep chests, and larger in the slender and broad-
• Vide Fig. 1.
38 EXLARGEMEXT OF THE HEART,
chested. Its size is greater at the close of an expiration than after an inspiration, and the difference is, of course, marked in proportion as these respiratory acts are forced. These are variations irrespect- ive of those occasioned by disease. Moreover, in the dead subject, the conditions of the heart and lungs affecting their mutual rela- tions are by no means uniform. The lungs collapse and shrink away from the heart more or less, according to contingencies which are independent of disease, and the state of the heart, as regards the quantity of blood remaining in its cavities, depends on the mode of dying and other circumstances. But happily these varia- tions are not sufficient to i^ender unreliable the signs incident to diseases of the heart.
During life, the space within which the heart in health is un- covered of lung and in contact with the chest, in other words, the limits of the "superficial cardiac region," and the boundaries of the heart beyond these limits, or the "deep cardiac region," may be determined by means of percussion. With sufficient care and prac- tice, the two regions just named, to the left of the median line, may be determined on the chest in the majority of persons. Their limits, in fact, are often so distinctly definable that, in view of the changes which occur in the heart and lungs after death, the dimen- sions obtained by percussion during life represent more fairly the normal relations of these organs than measurements with the parts exposed to view in the dead subject. The limits of the superficial cardiac region are best ascertained by light percussion, commencing at the centre of the region. The upper limit in seventeen healthy persons in whom it was carefully ascertained was the cartilage of the fourth rib ; in some the upper and in others the lower margin of the cartilage near the sternum. The outer limit on a transverse line passing through the nipple is at a point varying from half an inch to an inch and a half within the nipple, the average distance in twenty-two persons being a small fraction (g^gth) over an inch. The apex-beat, which is generally either seen or felt, determines the outer limit at the base of the triangle. The percussion-sound at this point is sometimes tympanitic from transmitted gastric resonance, the quality and pitch of sound denoting its source. In determining the lower boundary of the region, the line of demarca- tion between the liver and the lower border of the heart is to be distinguished by the percussion-sound. This, which Dr. Walshe calls "one of the most difficult practical problems in the art of percussion," is readily done in most persons. Percussing from a
SUPERFICIAL AND DEEP CARDIAC REGION'S, 39
point over the liver towards the heart, viz., in the epigastrium in a direction upwards and outwards to the left, the flat, short, high, liver-sound, at a little distance above the xiphoid cartilage, gives place to a sound dull but not flat, longer and lower in pitch. Con- necting now the several points, already marked on the chest with ink or some coloring substance, we have a diagram representing the superficial cardiac region sufficiently exact for ascertaining its normal dimensions in the living subject. The average transverse diameter, measured from the median line to the outer limit, a little below, the level of the nipple, in twenty-three healthy persons, was a small fraction over three inches, the maximum width being four, and the smallest two and a half inches. The average vertical diameter, measured on the median line in sixteen healthy persons, was two and a half inches, the maximum three, and the minimum one and three-quarter inches.
Tn determining the boundaries of the heart beyond the limits of the superficial cardiac region, that is, the extent of the "deep cardiac region," or, in other words still, the border of the preecordia, forcible percussion is requisite, but not force enougli to occasion pain. In mapping on the chest this space, the course enjoined by Bouillaud has decided advantages, viz., commencing at some dis- tance from the heart and percussing towards the prsecordia. The points at which the percussion-sound is modified, i. €., distinctly dull, being marked and connected by lines, the space occupied by the heart is delineated on the chest ; and if the limits of the super- ficial cardiac region are delineated on the same chest, we have two concentric diagrams representing the two regions. Attention to the pitch of the percussion-sound is of great assistance in appreciat- ing the dulness within the deep cardiac region, a change in this respect being more readily recognized than the difference in the degree of resonance. Taking the nipple as a landmark, in twenty- five healthy persons (all males) the left border was precisely at the nipple in sixteen ; in six instances, it was within the nipple, the greatest distance being seven-eighths of an inch, and the smallest three-eighths; in three instances, it was without the nipple, being half an inch beyond in two, and three-eighths of an inch in the remaining instance.' The prascordial region, as determined by percussion on the living body, in the majority of instances, extends
' It should be stated that these, as well as the preceding results of percussion, were obtained by percussing -srhile the persons were in a sitting posture.
40 ENLAEGEMENT OF THE HEART.
somewhat farther to the left of tlie sternum than when this region is viewed in the dead subject, a fact doubtless owing to the presence of a larger quantity of blood within the cavities of the left side of the heart during life. On the right side of the sternum, on a level with the nipple, dulness is generally appreciable within a space varying from half an inch to an inch. The percussion-sound over the third rib near the sternum is generally sufficiently modi- fied on percussing from above downwards to indicate the base of the heart in this situation.*
The foregoing details, which have been given as succinctly as possible, are essential as constituting the basis of the physical signs of enlargement of the heart. The latter, after these preliminaries, may be briefly presented. The area of prascordial dulness exceeds the limits of health in proportion as the volume of the heart is abnormally increased. The effect of an enlarged heart is especiallj^ manifest in the superficial cardiac region. The heart, in proportion to its augmented bulk, pushes aside the borders of the lungs, leaving a larger portion of its anterior surface uncovered and in contact Avith the thoracic walls. The superficial cardiac region becomes, of course, proportionately larger than in health. This effect is certainly the rule, and the exceptional instances described by some writers^ in which the heart buries itself beneath the lungs, leaving its anterior surface covered to the same extent as in health, must be extreraelj^ rare, assuming the volume of the lungs to be nornial. The enlargement of the superficial cardiac region is espe- cially marked transversely to the left of the median line, owing to the heart increasing more in width than in length. The apex of the organ is generally removed to the left of its normal situation,
' The combination of percussion and auscultation, or auscultatory percussion, as proposed and practised by Drs. Cammann and Clark, of New York, is undoubtedly well adapted to determine witli ease and accuracy the boundaries of the heart. See New York Journal of Medicine, July, 1840. That this mode is not more gene- rally employed is because percussion, as usually practised, suffices for ordinarj^ practical purposes. The stethoscope recently invented by Dr. Cammann is well suited to auscultatory percussion. The publication by Drs. Cammann and Clark just referred to, contains the average dimensions of the space occupied by the adult heart in a series of examinations. The following are the mean results : —
Male. Female.
Vertical diameter . . 4 in. 0 lines 3 in. 7 lines
Transverse " . . 4 " 4 " 4 " 1 line
Right oblique " . . 4 " 10 " 4 " 10 lines
Left oblique ' " . . 3 " 10 " 3 " 7 "
2 Traite do Diagnostic, par Racie.
SIGN'S OBTAIXED BY PERCUSSION. 41
owing partly to tlie oblique position of the heart, and in part to the fixedness of the base of the organ, the latter, with the diaphragm below, offering mechanical resistance to much extension in a verti- cal direction. The apex being free, is moved readily in a lateral direction. The evidence, therefore, of the heart being abnormally uncovered of lung, and of the extent of its surface in contact with the chest, is obtained b}'' percussing from the median line towards the nipple and towards the point where the apex-beat is felt. The lateral diameter of the superficial cardiac region at the inferior boundary, i. e., between the median line and point of apex-beat, may be one, two, and even three inches greater than in health. The superficial dulness instead of ending an inch within a vertical line passing through the nipple, extends to this line, or from one to two inches beyond it. The presence of the apex-beat enables us to determine the diameter in this situation without practising per- cussion. This point may be more or less lowered, as well as carried to the left. It is frequently found in the sixth, and some- times even in the seventh intercostal space, the inferior boundary of the superficial cardiac region being, of course, proportionately lower than in health. Percussing next from the left margin of the sternum on or just below the level of the nipple, the superficial dulness may be found to extend to the nipple, or half an inch, an inch, or even farther, beyond it. The diameter of the region here will correspond to the abnormal width of the heart. Other things being equal, the enlargement of the heart transversely may be accurately measured by the extent to which the diameter of the superficial cardiac region in this situation is increased. Bxit it is to be borne in mind that the normal situation of the outer limit of this region is not the same in all persons. The average distance within the nipple is verj' nearly an inch, but the variation within the range of health, as has been seen, is from half an inch to an inch and a half. If the superficial dulness extend to Avithin half an inch of the nipple, or possibly even within a still shorter dis- tance, it may not be due to abnormal enlargement; and, on the other hand, in a person Avhose heart is normally covered by lung an inch and a half within the nipple, superficial dulness extending to a point within half an inch of the nipple would denote consider- able enlargement of the heart. If the area of superficial dulness proper to the individual be not known, an abnormal increase of its dimensions cannot in any case be assumed unless the lateral dia- meter extend nearlj'- or quite to the nipple. Here, as in other
42 ENLARGEMENT OF THE HEART.
instances, the extreme limits of healthy variation are of greater practical consequence than averages. In determining, however, whether the heart be enlarged or not, the distance from the apex to the median line is to be taken into account, and also the signs obtained by other methods of exploration than percussion.
The degree of dulness within the superficial cardiac region is, in general, greater than in health in proportion to the enlargement. In health, a portion of the heart is imbedded in lung sufficient to occasion the transmission of more or less pulmonary resonance over the whole of the praacordia. The degree of normal dulness differs in different persons. It is generally marked, and sometimes approaches to flatness. It is sufficient to render the limits of the region distinctly definable, except when great obesity exists, or, in the female, when the mammary development is unusually large. It is sufficiently intelligible that, in proportion as the lung is pushed aside in cases of enlargement, the dulness will be greater in degree than in health. In some instances it amounts to flatness. It is equally obvious that the sense of resistance felt in practising percussion will be marked according to the increased bulk of the heart.
It is important to bear in mind that increased extent and degree of superficial dulness are signs of enlargement of the heart, with this provision, viz., that the lungs are free from disease. The size of the area is affected by abnormal conditions of the latter organs, as well as the heart. In phthisis, the left lung is frequently con- tracted, so that the anterior margin is removed towards the border of the heart, leaving a larger portion of the heart's surface in con- tact with the thoracic walls, even though the size of the organ may be less than in health. A similar result follows chronic pleurisy, the lung not expanding, and resuming its normal volume suffi- ciently to cover the heart as in health. Happily, in these excep- tional cases the liability to error is slight, for the existence of tuberculosis is determined without difficulty, and the retrospective diagnosis of pleurisy is also easily made. The pra3Cordial space is not enlarged, and all doubt is removed by defining the boundaries of the deep cardiac region.
The relations of the heart and lungs are also affected by a variety of causes, irrespective of morbid conditions of either of these organs, such as enlargement of the liver, dilatation of the stomach, aneurism of the aorta, enlarged spleen, ascites, pregnancy, tumors in the me- diastinum, etc. These disturbing causes are generally determinable;
SIGNS OBTAINED BY PERCUSSION. 43
and the importance of not limiting exploration to tlie prascordia, but extending the examination over the chest and abdomen in order to exclude these and other affections which alter the normal disposition of the heart and lungs, is sufficiently obvious. Errors of diagnosis are sometimes attributable to neglect of this precaution.
The limits of deep dulness are not extended beyond those of superficial dulness proportionately to the degree of enlargement of the heart, but it is sometimes desirable to ascertain the actual space which the heart occupies. Percussing from without the heart to- ward the prgecordia, the lateral borders of the organ may generally be determined without great difficulty, and delineated on the chest. The enlargement of the deep cardiac region is not only manifested by dulness extending more or less without the left nipple, but also beyond its normal boundary to the right of the sternum. Not only the extent of this region, but the form of the heart may be deline- ated, and the latter is of diagnostic significance as respects the dis- crimination between hypertrophy and dilatation, the latter increasing- more than the former the width in proportion to the length of the heart.
The evidence afforded by percussion of enlargement of the heart is much less marked, if, in conjunction, the left lung be aflbcted with emphysema. This combination is not infrequent. The effect of emphysema of the left lung is to lessen and even abolish the superficial cardiac region. The anterior border of the lung may be extended forward so that the whole surface of the heart is covered. The heart, too, is often depressed below its normal situation by the pressure of the dilated lung. The co-existence of emphysema, thus, renders the area of the superficial cardiac region no longer an index of the existence and the degree of enlargement of the heart. The limits of the deep cardiac region are alone to be depended on, and they are not always, under these circumstances, easily defined. The combination renders the diagnosis difficult by impairing also concurrent signs of enlargement obtained by auscul- tation, inspection and palpation. Moreover, the symptoms of em- physema are liable to be confounded with those which are due to disease of heart. The individual cases in which this difficulty in diagnosis exists are easily recognized, for the signs of emphysema are sufficiently explicit; and in a certain proportion of these cases the diagnostician must be content to rely in a great measure on the well-known pathological association of the two affections, deter- mining the relative proportion of each approximatively.
44 ENLARGEMENT OF THE HEART.
Enlargement of the heart results from different pathological con- ditions. In addition to the two forms, to the consideration of which this chapter is devoted, viz., hypertrophy and dilatation, the organ acquires an abnormal size from the accumulation of blood within its cavities and the deposit of morbid products and fat on its surface. The question may be here raised, whether percussion furnishes data for the differential diagnosis of the different varieties of enlarge- ment. Hypertrophy or dilatation, as has been seen, may be limited to portions of the heart, or may disproportionably affect certain portions. It is stated that the dulness extends more to the left of the median line .when the left ventricle is the seat of enlargement, and is more manifest on the opposite side when the right ventricle is affected. The relations of the two ventricles, however, is such that, in view of the position of the heart and the movableness of the body and apex, the left border is extended in proportion as the right side is increased in size; and it may fairly be doubted whether, as a rule, the foregoing statement holds good clinically. The right or left auricle, belonging to the base which is comparatively fixed, when considerably enlarged, may occasion a greater relative extent of dulness on the corresponding side of the sternum. This remark is also applicable to distension of the cavities of the heart by the accumulation of blood. Great distension of the right side of the heart, which occurs in some cases of obstruction to the pulmonary circulation, may be manifested by an abnormal extent of dulness over the site of the rio'ht auricle; and this extent of dulness mav
CD J »/
be found to have diminished when the causes of obstruction are removed. The ability to distinguish between hypertrophy and dilatation by the percussion-sound is more than questionable. This is a nicety which the student should not attempt to acquire, for in proportion as he might imagine that he had made the acquisition, would be his liability to error in practically trusting to it. The same remark is applicable to the endeavor to determine by percus- sion that enlargement of the heart is due to the deposit of fat or morbid products on its surface. Very considerable enlargement in a transverse direction of the superficial and deep cardiac regions, however, is presumptive evidence that the increased bulk is due to dilatation rather than hypertrophy, for the former, more than the latter, tends to increase the width of the organ and also to give rise to excessive augmentation of size. On the other hand, if percussion show that the heart is considerably lengthened, and that the trans- verse enlargement is not to much extent disproportionate to the
SIGNS OBTAINED BY PALPATION. 45
vertical, tlie presumption is in favor of hypertrophy rather than dilatation.
Enlarged extent and degree of prascordial dulness are produced by liquid accumulation within the pericardial sac, as well as by enlargement of the heart. Both may co-exist, and then the evidence afforded by percussion of cardiac enlargement ceases to be available. The points of distinction between the prsecordial dulness due to liquid accumulation within the pericardial sac, and that due to enlargement of the heart, are important, and will be considered in connection with the subject of pericarditis.
2. Altered situation and extent of the apex-heat; impulses elsewhere than over the apex of the heart, and abnormal force of impulse, as deter- mined hy palpation.
The point at which the apex, or pointed extremity of the heart, presses with an impulsive force against the thoracic walls, is in the fifth intercostal space, the person examined being in the sitting- posture. Of twenty-five healthy persons examined, none presented an exception to this rule. In this intercostal space, the impulse is felt over an area varying from half an inch to an inch and a half, in health. The average transverse diameter of this area, in thir- teen persons, was a fraction (y^th) over an inch. The centre of this area, where the force of the beat is greatest, is situated within a vertical line passing through the nipple, at a distance from that line varying from two inches to three-eighths of an inch, the average, in eighteen persons, being a fraction (^th) over an inch. The distance from the median line to the centre of this area varies between three inches and five-eighths and tw^o inches and five- eighths, the average, in fifteen persons, being a fraction (xsth) under three inches. Measured from a transverse line passing through the nipple, the distance varies from an inch and an eighth to two inches, the average, in eight persons, being a fraction (7th) over one and a half inch. These are the relations of the apex-beat in the sitting posture. Deviations take place when the posture is changed, owing to the movableness of the apex and body of tlie heart. In the recumbent position on the back, the beat is frequently felt in the fourth intercostal space, the same relations laterally to the nipple and median line as in the sitting posture being preserved. The frequency with which this is observed has led some late writers to state, incorrectly, that, as a rule, the apex-beat is in the
46 ENLARGEMENT OF THE HEART.
fourth intercostal space.' Lying on the right side, the centre of the area within which the beat is felt is removed about half an inch nearer the sternum. Lj'ing on the left side, the beat is removed to the left, so that the centre of the area generally falls on a vertical line passing through the nipple, and the impulse is felt half an inch without this line. The respirator}'" movements sometimes affect the situation of the apex-beat. I have not observed it to be lowered by a full inspiration, but it is occasionally raised from the fifth to the fourth intercostal space by a forced expiration, the persons examined in the sitting posture. The apex-beat is not unfrequently inappreciable to the touch in healthy persons, in the sitting pos- ture. The persons in whom it is wanting have generally deep chests. Thickness of the soft parts also prevents it from being felt. It is lost in the recumbent position on the back in some instances in which it is felt when the person is sitting. It is still oftener lost when the person lies on the right side, but very rarely when the position is on the left side. In the latter position it is sometimes felt when not appreciable in any other.
The force of the impulse varies in different persons. It is rarely strong when the person is tranquil and free from mental agitation. It is generally quite feeble. It is almost invariably less when the person lies on the back than in the sitting posture ; and it is still more diminished, when not lost, if the position be on the right side. Lying on the left side increases the impulsive force ; the beat is strongest in this position. The sensation on applying the fingers over the area of the apex-beat, as remarked by Dr. Walshe, is that of a gliding as well as an impulsive movement. It is not that of a percussion or blow. It is suflQcieutlj^ clear, on a little reflection, that the apex of the heart does not withdraw itself from the thoracic walls, and then come into forcible contact through an open space. The pressure of the atmosphere on the exterior surface is sufficient to prevent the heart receding from the chest, except so far as it is displaced by intervening pulmonary tissue. The beat must, of necessity, be produced by movements incident to the changes in form of the organ, and not to the tilting forward of the apex, as was formerly imagined.
The mechanism of the heart's impulse has been a fruitful theme for discussion. It does not fall within the scope of this work to consider the various theories which have been proposed. The
' Vemeuil, 1852, Racle, op. cit.
MECHANISM OF THE HEAET's IMPULSE. 47
subject, however, naturally presents itself in this connection, and claims a few remarks. It is generally admitted that the beat occurs synchronousl}'' with the S3^stolic contraction of the ventricles. This is denied by some, and a theory which attributes it to the shock of the current of blood propelled into the ventricles by the contraction of the auricles, numbers among its supporters several distinguished names. Without discussing this theory, the improba- bility that the auricles possess sufficient power of contraction to account for the phenomena pertaining to the impulse, and the fact that the beat and the pulsation of the large arteries near the heart (e. (/., the carotids) occur without any appreciable interval' of time, together with the observations of vivisectors, seem to render it con- clusive that the commonly received doctrine is correct.^ It may also be assumed that the impulse is produced by the apex of the heart, as, in fact, is assumed in the expression "apex-beat." The question, then, resolves itself into this: In what manner do the systolic movements of the heart cause the apex to press with a certain degree of impulsive force against the thoracic walls? This question is in a great measure answered if it be conceded that the apex of the heart is elongated during the ventricular systole. Some of the older anatomists, Galen, Yesalius, Harvey, and, later, John Hunter, entertained this view ; while it was denied by Steno, Lancisci, Haller, and others. More recently, Dr. Hope and others, resorting to vivisections practised on animals of large size, were led to conclude that during the systolic contraction of the ventricles the heart is shortened by an approximation of the apex towards the base. It is difficult to understand how careful observers should be deceived in this regard, but, in the mind of the author, this con- clusion is undoubtedly erroneous. Drs. Pennock and Moore, in their vivisections in 1839, satisfied themselves that the heart elon- gates during the ventricular contractions, and they even measured the extent of elongation. For several years. Prof. Dalton, of New York, has been accustomed, in his courses of instruction in Physio- logy, to demonstrate this fact, and the author has had an opportunity of witnessing a demonstration by him on an animal of considerable
' The reader, desirous of knowing the grounds on wlaich the diastolic theory of the heart's impulse is sustained, is referred to the treatise on General Pathology, by Prof. Alfred Stille ; and for a still more elaborate exposition to the Traits Ex- perimental et Clinique cV Auscultation, par .J. H. S. Beau, Paris, 1S56. A review of the latter by the author is contained in the American Journal of Medical Sciences, No. for January, 1857.
48 ENLARGEMENT OF THE HEART.
size (a sheep), while engaged in writing this chapter. The sj'stolic elongation of the heart is therefore assumed in this work, in oppo- sition to the statements of most, if not all previous writers on the diseases of this organ.' In elongating, the heart performs a revolv- ing or spiral movement from left to right.^ It is thus easy to per- ceive that the extremity of the organ presses against the chest with an impulsive, boring movement^ more or less forcible, according to the power of the ventricular systole. Admitting the correctness of these statements, the mechanism of the impulse seems sufficiently explained ; but the inquiry arises, is the elongation of the apex due directly to the muscular contraction of the ventricles, or to an intermediate force derived from the blood impelled by the systole against this extremity of the heart? A German theory, ascribed to Gutbrod, but, according to Dr. Markham, proposed by Dr. Alderson in an English quarterly journal as long ago as 1825, attributes the impulse to a reversed current of blood within the ventricles. This is known as the "Segner's water wheel," and the " recoil" theory. It is adopted by Prof. Skoda, and by the author of a late English work on diseases of the heart. Dr. Markham. The explanation of the impulse, according to this theory, is thus given by Dr. Gutbrod :^ " It is a well-known phj^sical law, that when a fluid escapes from a vessel, the equality of pressure pro- duced by the fluid on the walls of the vessel is lost, for there is no pressure at the opening whence the fluid escapes; but at that part of the vessel which is opposite to the opening, the pressure is still exerted. This pressure it is which sets Segner's wheel in motion, produces the recoil of firearms, etc. By contraction of the ven- tricles, the pressure which the blood exerts upon the walls of the heart, opposite to the opening whence the stream escapes, causes a movement of the heart in a direction contrary to that of the stream of blood, and by this movement the impulse of the heart against the walls of the thorax is produced. The heart is driven in a direction contrary to that of the arteries, with a force proportionate
' The modern revival of the belief in the systolic elongation of the heart, may be characterized as the American doctrine. It does not appear to have been as yet adopted on the other side of the Atlantic. Vide Dalion^s PIvjsiology, Phila- delphia, 1859.
- The movement of the apex from left to right with the ventricular systole, is sometimes very ai^parent when the thoracic walls are much thinned by emaciation. Vide case of M., Private Records, vol. x. page 64S.
^ A Treatise on Auscultation and Percussion, by Dr. Joseph Skoda. Translated l)y Dr. Markham.
APEX-BEAT IN ENLAEGEMENT. 49
to tlie quantity and the velocity of tte current of blood." This theory is controverted by different writers ;' but without entering into a discussion of its merits, it is rendered gratuitous by the fact that the elongation of the heart occurs when its cavities are entirely free from blood. If the heart be quickly removed from a living animal, the auricles opened and the organ placed in a vertical posi- tion with the base downward, the contractions of the ventricle continue for several minutes, and the elongation in this experiment is conspicuously manifest.^ This shows conclusively that the elongation takes place independently of the current of blood.^
Directing attention now to the signs of enlargement and of hyper- trophy obtained by palpation, those relating to the situation of the apex-beat are to be first noticed. The apex-beat is carried to the left of its normal situation and frequently lowered when the bulk of the heart is increased. These changes are among the most constant and reliable of the signs of enlargement. The beat may be felt one, two, or even three inches without the nipple. It may be found in the sixth and even in the seventh intercostal space. The distance to which it is removed in these directions, assuming that the alterations depend exclusively on the increased bulk of the heart, constitutes a criterion for estimating the amount of enlarge- ment. It must, however, be considered that abnormal conditions extrinsic to the heart alter the relations of the apex to the walls of the chest, such as enlargement of the left lobe of the liver, disten- sion of the stomach, ascites, enlarged spleen. These and others
' Vide uote to French translation of Skoda's Treatise, by tlie translator, Dr. Aran.
^ For an illustration of this experiment, vide Dalton's Physiology.
^ Prof. H. Bamberger, of Wiirzburg, has reported a case in which a healthy man attempted to commit suicide by stabbing himself in the breast with a sharp knife. The wound was at the lower margin of the fifth rib, within the nipple, and the man had evidently selected the spot where the heart's impulse was felt. On pressing his finger into the wound, Prof. B. felt the apex of the heart distinctly, the peri- cardium evidently having been opened. He availed himself of the opportunity to study the movements of the heart, and he states as follows : " When my finger was introduced from the point toward the back, I could convince myself with the greatest certainty that at every systole the hardened and pointed apex slipped down along the front wall of the chest, somewhat to the left and a little below the lower margin of the wound, whilst in the diastolic movement the apex retreated upward and could not be felt." This observation, which affords valuable con- firmatory evidence of the systolic elongation of the heart, is not ofl"ered by the reporter as such ; he regarding it as settled that the vertical diameter of the organ is shortened in the systole.
4
50 ENLARGEMENT OF THE HEART.
pertaining to the abdomen may remove the apex to the left, but without lowering it. An aneurismal or other tumor situated above the heart may give rise to the same change with depression. An emphysematous left lung pushes the heart downwards, but gene- rally towards the epigastrium, often giving rise to an impulse in this situation, while the normal apex-beat is suppressed. These extrinsic conditions are, of course, to be excluded before the abnor- mal position of the apex can be regarded as a sign of enlargement of the heart. The limits of variation in health, in different posi- tions of the body, are to be borne in mind in deciding whether the situation be normal or abnormal. If the patient be examined in the sitting posture, and the apex-beat be found in the fifth inter- costal space, it is not lower than natural ; but if the patient lie on the back, the chances are about equal that if the beat be in that space it is lowered ; but if it be abnormally lowered, it will also be removed to the left in the great majority of cases. With reference to its relations laterally, it may be within half an inch of a vertical line passing through the nipple, or three and a half inches from the median line, without exceeding the range of healthy variation. If on a line with the nipple, or four inches from the median line, its situation is abnormal, provided the patient be either sitting or lying on the back. In the majority of the cases of enlargement which come under the notice of the physician, it is found without the line of the nipple.
The area in which the apex-beat is felt (averaging about an inch in health) is extended in cases of enlargement of the heart. The extremity of the organ is less pointed than in health ; it is blunt or rounded, and consequently a broader surface comes into contact with the thoracic walls during the systolic impulse. This is a sign of some importance taken in connection with other signs denoting enlargement either by hypertrophy or dilatation.
In cases of hypertrophy of the left ventricle, the force of the apex-beat is abnormally great in proportion to the increased thick- ness of the walls, provided that the form of the apex be not greatly altered, the muscular power of the organ not weakened, or the completeness of the ventricular contractions not prevented by con- traction at the aortic orifice, or other causes. An abnormal force of the apex-beat is associated with change in situation and exten- sion of the area in which the beat is felt. The force of the beat thus associated is an important sign as showing that the enlarge- ment is due to hypertrophy rather than to dilatation, or that the
FORCE OF APEX-BEAT IN HYPERTROPHY. 51
former predominates. la proportion as the left ventricle is hypertrophied rather than dilated, other things being equal, the force of the beat is augmented. Augmented force of the beat, however, may be due simply to increased muscular activity of the organ without enlargement. The heart is aS'ected functionally or dynamically without organic disease. The beat is augmented in the same manner as under excitement by active exercise or mental agitation. How is it to be determined whether the abnormal force of the beat be due to hypertrophy or simply to morbid excitement of the organ ? The sensation in the latter case is that of increased action, and in the former case of increased power, of the impulsive movement. This distinction is generally appreciable. The beat in hypertrophy is felt to be produced by a powerful contraction of the ventricle ; the impression conveyed by the touch is that of a prolonged, sluggish, as well as strong impulse. In mere functional excitation, the beat is more abrupt, quick, and brief, giving the idea of violence rather than of strength. The distinction is import- ant, and would be vastly more so were the discrimination to rest solely on the difference, as respects the force of the beat. But in hypertrophy there are the coexisting signs of enlargement which are wanting in an afiection simply functional. Increased force of the apex-beat is by no means a constant sign of hypertrophy. On the contrary, the beat may be suppressed. This may depend in part on the change of form which the extremity of the organ undergoes, and partly on the weakness incident sometimes to enlargement, even when the muscular tissue is augmented. The latter belongs to a late period in the progress of the disease. Sup- pression of the apex-beat is much more apt to occur in cases of dilatation than in cases of hypertrophy, because in the former the extremity of the organ is more blunted and weakness more marked. Other signs of cardiac enlargement and hypertrophy than those relating to the apex-beat are obtained by palpation. Abnormal impulses may be felt in other situations than over the apex. Occa- sionally, in health, in addition to the apex-beat in the normal situa- tion, an impulse is appreciable in the fourth intercostal space, and, in some instances, in the epigastrium to the left of the xiphoid car- tilage, A double impulse, viz., in the fourth and fifth, or in the fifth and sixth intercostal spaces, is not unusual in cases of enlarge- ment, and especially enlargement by hypertrophy. In some cases impulses are felt in three and even in four intercostal spaces. In these cases the lowest point of impulse is the farthest removed from
52 ENLARGEMENT OF THE HEART.
the median line, and the impulses above are, severally, situated nearer the sternum. In a patient under observation at the time of writing, impulses are felt and seen in the fifth, fourth, third, and second intercostal spaces. The impulse in the fifth intercostal space is situated an inch without a vertical line passing through the nipple; that in the fourth, is just within the nipple, and the im- pulses in the third and second spaces are near the left margin of the sternum.^ The explanation of these additional impulses in cases of enlargement is, the heart being in contact with the thoracic walls over a larger space than in health, in other words, the area of the superficial cardiac region being enlarged, the movements of the organ are communicated to the yielding spaces between the ribs. This does not take place, as a rule, in health, in consequence of the interposition of lung save over a comparatively limited space. The impulsive movements, elsewhere than over the apex, are not always coincident with the ventricular systole; in other words, the elevations or outward motions at the several points at which the movements are observed, do not take place in unison, but in some instances in alternation. Thus when movements are felt in the fourth and sixth intercostal spaces, that in the sixth is the apex-beat and systolic, while that in the fourth may occur with the diastole of the ventricles. Alternation of the impulsive move- ments in these two intercostal spaces, is not unfrequently observed in cases of hypertrophy. The superior or diastolic movement was called by Dr. Hope the back-stroke of the heart. It is stated that this is sometimes observed in healthy persons when the heart acts with unusual vigor.^ Generally in the cases in which a diastolic movement is observed, retraction of the intercostal space takes place during the ventricular systole, due to the flattening of a portion of the heart, and the movement of impulsion which alter- nates with the apex-beat is, in fact, only the elevation of the space to the level from which it was depressed. In other words, the space over the body of the heart yields to atmospherical pressure and follows the retreating ventricular walls during the systole, resuming its level when the heart assumes a more globular form during the diastole. The impulsion is not strong, and may be visible when not distinctly felt. In the case just referred to in which four distinct points of impulse are observable, the impulsion
' Case of Bergmann. Hospital Records, vol. xiii.
2 Bellingliam on Diseases of tlie Heart. Dublin, 1853. Part I. p. 61.
ADDITIONAL IMPULSES IN HYPERTROPHY. 53
in the fifth, third and second intercostal spaces appears to take place during the systole, and that in the fourth intercostal space during the diastole of the ventricles. The three former are stronger than the latter. An impulse over, or a little below the base of the heart, i. e., in the third and possibly in the second intercostal space, is referable to the expansion of the upper portion of the organ during the systole. The fact of this expansion and the force with which it takes place are shown by grasping the heart near the base in a living animal. A strong pressure is felt when the ventricles contract. It is not difficult to understand that the change of form at the base should communicate an impulsive movement to the intercostal space when the heart is abnormally uncovered of lung, and also in some instances of palpitation without organic disease, when the action of the heart is notably augmented. It is possible that, in some instances, the dilatation of the pulmonary artery following the systole of the ventricles, or the shock produced by the sudden arrest of the column of blood in consequence of the expansion of the sigmoid valves during the ventricular diastole, may give rise to an impulsive movement which may be felt in the second left intercostal space. Dr. Sibson states that a diastolic impulse is sometimes felt in this situation when, from pulmonary disease, the left lung recedes at this point, leaving the artery unco- vered and in contact with the parietes of the chest.^ An impulse situated here, referable to the pulmonary artery, is more likely to occur, for obvious reasons, in cases of hypertrophy of the right ventricle and when there exists obstruction to the pulmonary cir- culation. Laennec entertained the idea that an impulse on the left side at the base of the heart was sometimes due to the contraction of the left auricle. Aside from the fact that the greater part of the auricle is covered by the large arteries emerging from the heart, and the improbability of its ever contracting with sufficient force to communicate a perceptible impulse to the walls of the chest, it is difficult to understand how any other than a movement of retrac- tion can accompany its systole. It seems far more reasonable to attribute an impulse in this situation, either to the ventricles or to the pulmonary artery. If there be free regurgitation through the mitral orifice, it is intelligible that the retrograde current of blood impelled by the force of the systole of the left ventricle may occa- sion an impulse over the auricle. This is perhaps the explanation
• Medical Anatomy.
54: ENLAKGEMENT OF THE HEART.
in some instances, at least, in which an auricular impulse has been supposed to exist. Dr. Stokes reports a case in which an impulse was felt on the right side of the sternum, evidently, from the appearances after death, due to a retro-current through the tricuspid orifice, the right auricle being enormously dilated and its walls attenuated,^ It is evident that an impulse produced in this way through the left auricle involves the supposition of auricular dilatation. It is indeed possible that without insufficiency of the mitral or tricuspid valves, an impulse may be produced by the momentum communicated to the blood contained within a dilated and distended auricle by the backward pressure of these valves during the ventricular systole.
It is to be borne in mind that the occurrence of movements in the intercostal spaces, impulsive or retractive, involves contingencies irrespective of cardiac disease. They are more likely to occur in persons who have flattened chests and long sternums than in those with a thoracic conformation the opposite of this. They require a certain thinness of the parietes of the chest, and are more marked in proportion as the thoracic walls are attenuated. They may be obvious when the heart is excited, and not appreciable when the organ acts feebly. They may be due to abnormal conditions per- taining to the lungs, the heart remaining sound. They are ob- served in some instances in which the pulmonary substance is withdrawn from the heart, as after the absorption of liquid effusion in pleurisy affecting the left side and in some cases of tuberculosis. An effect of these affections is often to leave an enlarged area of the heart's surface in contact with the walls of the chest, and, under these circumstances, the motions of the organ may communicate corresponding movements to the intercostal spaces. Hence, impul- sive movements elsewhere than over the apex of the heart are never signs of enlargement, unless associated with altered situation of the apex-beat and other signs indicating that the bulk of the organ is increased.
The conformation of the chest in some persons is such that an impulse referable to the heart is felt, in health, in the epigastrium by directing the fingers upwards and outwards beneath the false ribs on the left side. In the majority of persons the organ is too
' On Diseases of the Heart and Aorta, Am, ed., p, 290. Dr. Stokes attributes the impulse over the dilated auricle, in that case, to the auricular contraction ; but as he states that it was synchronous with the ventricular systole or the first sound of the heart, it seems clearly to have been due to a regurgitant current.
IMPULSE IN EPIGASTRIUM. 55
far removed for its action to be appreciable in this situation. Cardiac impulse in the epigastrium is therefore usually, but not invariably, a sign of disease. As a morbid sign, it denotes either enlargement of the heart or displacement in a downward direction. It is a sign by no means present in most cases of enlargement of the heart. The oblique position of the heart and the resistance offered by the diaphragm and the left lobe of the liver prevent much descent towards the epigastrium. These circumstances apply, as has been seen, measurably, to cases in which the enlargement predominates in the right as well as the left ventricle. But it is undoubtedly true that an impulse in this situation is more likely to occur as a result of enlargement of the right than of the left ven- tricle. When it proceeds from a cardiac affection, it may be con- sidered as affording strong presumptive evidence that the right ventricle is enlarged. A strong impulse, under these circumstances, goes to show that the enlargement involves not merely dilatation, but hypertrophy. The question to be first settled is. Does it pro- ceed from increased size of the heart? This question may be settled frequently by reference to the apex-beat. If the beat be in its normal situation, and there are no signs of enlargement, the impulse in the epigastrium is probably normal. It is not a sign of disease. But if the apex-beat be removed to the left of its normal position, it becomes a sign of enlargement of the right ventricle. When this is the case, other signs of enlargement will also be present. The diagnostic value of the sign, thus, when it is attri- butable to a cardiac affection, consists in its indicating that the right ventricle is the seat of enlargement. When it is determinable that the epigastric impulse is due to cardiac enlargement, the extent of the impulse will, in some measure, be an index of the amount of increase of the bulk of the right ventricle, and the power of the impulse will be in proportion as the enlargement is by hypertrophy, provided that the organ is not weakened from any cause, or pre- vented from contracting completely. The impulse is communicated in some instances not only to the epigastrium, but to the lower part of the sternum, and it is sometimes sufficient to cause a movement perceptible to the eye and touch, which extends over the site of the liver. When due to displacement of the heart, in the great majority of instances it is dependent on emphysema affecting the left lung. The dilated lung presses the heart downwards, overcoming the resistance offered by the diaphragm and liver, and the action of the right ventricle is felt in the epigastrium. The signs and symp-
56 ENLARGEMENT OF THE HEART.
toms of emphysema are sufficient to establish, the fact that this cause of displacement exists. The apex-beat, under these circum- stances, is frequently or generally wanting. Emphysema, however, induces enlargement of the heart, seated primarily and especially in the right ventricle. The epigastric impulse, tiierefore, may be due to both causes combined, viz., enlargement and displacement. To determine the proportion which each bears in the production of the sign is not easy. If the boundaries of the heart are determin- able by percussion, or if the situation of the apex-beat can be ascertained, this point may be settled with much precision. In examining the epigastrium with reference to the evidence of car- diac enlargement, it is important not to confound an impulse undoubtedly referable to the heart with pulsations often felt in that situation which are only indirectly attributable to the heart's action. In some thin persons, the beating of the descending aorta may be here felt ; and in connection with hysteria and other nervous affections, especially when accompanied by gastric tym- panites, strong pulsations are perceived in the epigastrium, which are said not to be uniformly synchronous with the heart's move- ments, and the mechanism of which it is not easy to explain. It is not difficult by means of palpation either to trace these pulsations directly to the heart or to isolate them from the latter.
The action of the heart is frequently attended by a shock felt by the hand or the head applied over the praecordia. Sensible move- ments are also sometimes communicated to the ribs, as well as the intercostal spaces, and they may extend over the preecordia. When the heart is tranquil, in health, a shock is rarely if ever perceived. The fifth rib is occasionally slightly raised by the movements of the apex during the systole. In disease, these effects of the heart's action are often marked. A perceptible and more or less forcible shock attends certain palpitations which are merely functional. The heart appears to act with violence. It seems to knock against the ribs. The sensation, in some instances, is as if the chest were struck with a hammer. The patient is painfully sensible of the force of the impulsion, while, in health, if the heart be not excited, its movements take place without the mind being cognizant of them. The violence of the action is shown by the movements of the body, of the dress, of the bedclothes. The instances related of fracture of the ribs and detachment of the costal cartilages by the force of the heart's action are doubtless apocryphal, but the shock is sometimes very great. It may be limited to the apex or felt at
HEAVING IMPULSE IN HYPEKTEOPHY. 57
the base, and, indeed, over the whole pr^cordia. Alone, the shock, however violent, only indicates excited action of the heart. It does not, of necessity, imply organic disease. It may be due simply to the fact that the heart acts with spasmodic or convulsive quickness and force. It is represented by the intense action incident to fear and some other emotions. If it be inorganic or functional, it is usually temporary, unattended by physical signs denoting organic lesions, and characterized by circumstances which will be hereafter considered as distinctive of nervous disorder or palpitation. Or- ganic disease, it is true, is often attended by violent action of the heart, but the significance of the latter as a sign of the former depends on the coexistence of other signs which are more unequi- vocal ; and, on the other hand, organic disease is often present when the heart's action is more feeble than in health. A strong heaving movement of the ribs or the prrecordia is, however, highly significant of enlargement by hypertrophy. This is quite different from the shock which has just been described. It is a compara- tively sluggish, prolonged, powerful elevation of the thoracic walls. The head, applied as in immediate auscultation, is raised, and, by the hand placed over the praecordia, the heart is felt to act with abnormal strength. The shock, due to intense functional excite- ment, proceeds merely from exaggerated action of the heart ; the heaving movement in hypertrophy involves, in addition, increased power of the muscular contractions of the organ. Moreover, in the latter case, the surface of the heart being in contact with the thoracic walls over a larger area, the extent of the impulsive movement is greater. The distinction just drawn is the same as has been already pointed out in contrasting the prolonged, power- ful apex-beat of a hypertrophied heart with the smart, sharp, violent impulse which only indicates excited activity of the ven- tricular systole. The distinction in both instances is practically important, but in discriminating between functional disorder and organic disease, in practice, the diagnostician will, of course, be guided by the absence or concurrence of other signs. It is hardly necessary to state that heaving of the prgecordia is not uniformly present in hypertrophy. The presence of this sign involves, as a condition, a degree of functional activity proportionate to the augmented thickness of the ventricular walls; in other words, it will not be present if the muscular power of the heart be weakened from any cause, notwithstanding the augmented bulk of the organ. Clinical observation, in fact, shows that a heaving impulse is often
58 EXLARGEMEXT OF THE HEART.
wanting in cases of hypertrophy. While, therefore, the presence of this sign is evidence of the existence of hypertrophy, its absence is by no means proof that hypertrophy does not exist.
3. Abnormal modifications of the heart-sounds; diminished extent and degree of the respiratory murmur and of vocal resonance within the lyrsecordia, as determined by auscultation.
The clinical importance of abnormal modifications of the heart- sounds has relation more to valvular affections than to enlargement of the heart. They are, however, by no means unimportant in connection with the latter. And here, as in treating of the physical signs embraced in the two classes already considered, it will be necessary to premise some account of the heart-sounds in health. To enter into a discussion of the numerous theories which have been advanced with regard to the mechanism of these sounds, would be tedious and unprofitable, as well as foreign to the prac- tical character of this work. I shall limit myself to a concise state- ment of points which are essential as preliminary to the study of the phenomena of disease ; and I shall devote to these less space in consequence of having recently considered them in a special publication, to which the reader is referred for a fuller exposition of the subject.'
The two heart-sounds, which together form the beat or revolu- tion of the heart, are called the first and second, or the systolic and diastolic sound. By the latter terms, it is implied that the first sound occurs during the systole and the second sound during the diastole of the ventricles. This, although called in question by some, may be assumed as sufficiently established.^ These sounds, respectively, have their maximum of intensity, and their characters are best studied in different situations, viz., the first sound over the point where the apex-beat is felt, and the second sound just above the base of the heart, in the intercostal space between the second and third ribs near to the sternum. Studied in these different situations, the two sounds differ as respects duration, pitch, and quality. The first sound, over the apex, is longer, lower, and has
• On the Clinical Studj of the Heart-Sounds in Health and Disease. Prize Essay. Transactions of the American Medical Association, vol. xi., 1S58.
^ M. Beau contends that the first sound is due to the auricular contractions. Op. cit.
HEAKT-SOUNDS IN HEALTH. 59
a booming^ quality. The second sound, in the second intercostal space near the sternum on either side, is shorter, more acute, and has a flapping or valvular quality. These differences in characters between the two sounds are generally well marked when the com- parison is made in the different situations mentioned, but, as will be seen presently, they are much less marked in other situations within the prsecordia. The sources of each of the sounds, and the parts concerned in its production, are important to be considered. "With reference to these and other points, we will notice each sound separately, commencing with the second sound.
The second sound succeeds the first after an interval extremely brief, but, w^hen the beats of the heart are not much accelerated, distinctly appreciable. It is estimated that the duration of this interval and the second sound combined is equal to that of the first sound, or of the longer interval which separates the second sound from the succeeding first sound, the latter interval and the first sound being about equal in duration. This sound, i. €., the second, as already stated, is best studied just above the base of the heart, in the space between the second and third ribs, near to the sternum. If the second sound be compared on the two sides of the sternum, a difference in pitch and other characters is generally apparent. On the right side the sound is more acute, more abrupt, louder, and apparently nearer the ear. These differences, taken in connection with the anatomical relations of the aorta and pulmonary artery in these situations, and also with clinical facts pertaining to disease, warrant the conclusion that, when a disparity exists, the sound on the left side emanates from the pulmonary artery, and that on the right side from the aorta. The sound in both situations has an unmixed, valvular quality, and, in view of the results of experi- ments made on living animals, and the effects of disease, it may be assumed that the valves of the aorta and pulmonary artery are the parts immediately concerned in its production. There is, then, a pulmonary second sound, due to the expansion of the valves of the pulmonary arter}^ succeeding the ventricular systole, and an aortic second sound, referable to the semilunar valves of the aorta. The second sound of the heart presents the characters of that due to the pulmonary valves, at the inferior border of the organ, i. e., just above the xiphoid cartilage in some persons ; occasionally, also, in
' The term booming, borrowed from Dr. Walshe, has not a very definite signifi- cation ; but expresses a difference in quality difficult to be described, although easily appreciated by the ear.
60 ENLARGEMENT OF THE HEART.
the third intercostal space on the left side and over the body of the heart, within the superficial cardiac region. Elsewhere, within the prrecordia, and at points removed from the pmecordia, wherever the second sound is heard, it presents the characters distinctive of the sound produced at the aortic orifice. These facts are ascertained by comparing, in a sufficient number of healthy persons, the second sound, as heard at different points, with that heard in the second intercostal space on the right and left side. It follows from the facts just stated that the aortic second sound is much more intense and widely diffused than the pulmonary, the latter, in some persons, being distinguishable alone in the second intercostal space on the left side ; sometimes, indeed, the aortic sound predominates even in that situation. The second sound of the heart maintains its distinct- ive characters of pitch, duration, and valvular quality, unaffected by the causes which affect the movements of the heart within the limits of health, such as exercise, mental agitation, etc. Its intensity even is not much affected by these causes. These facts show its unmixed character, in other words, that it consists of a single element only, a valvular element, in this res|)ect differing from the first sound of the heart.
The first sound of the heart, studied at the situation where its intensity is greatest, viz., over the apex of the organ, is a mixed sound. In this situation, it is usually accentuated^ that is, in the succession of the two sounds the stress falls upon the first, while at the base of the heart, and at other points, the accent is on the second sound. The mixed nature of the first sound is shown by the difference which it presents on auscultation over the apex, and at other points within the prsecordia ; by contrasting its characters as heard when the stethoscope is firmly placed directly on the sur- face of the chest with those which it presents when some soft material is interposed between the instrument and integument, or when the instrument is imperfectly applied ; by auscultating over the apex when the person examined is placed in different positions, and taking into consideration modifications incident to certain diseases and peculiar to certain persons in health.' The clinical study of this sound in health and disease leads to the conclusion that it is composed chiefly of two different elements. One of these elements consists of a valvular sound, due to the action of the
' In the prize essay already referred to {Trans. Am. Med. Association, vol. xi., 1858), the author gives a full account of the results of the clinical study of this sound under the different circumstances mentioned above.
HEAET-SOUNDS IN HEALTH. 61
mitral and tricuspid valves. The other element, in the author's opinion, proceeds from the movement of the apex of the heart against the thoracic walls. In a practical point of view, however, it is unimportant whether the latter element be thus explained or whether it be accounted for on the hypothesis of a sound adequate to its production, due directly to muscular contraction. Eeferring it to the movement of the apex against the thoracic walls, this element may be called the element of impulsion^ and the other ele- ment the valvular element} These names will be employed in this work to distinguish from each other the two elements composing the first sound.
These two elements of the first sound are combined in different proportions in different situations in which auscultation is practised, in different positions of the body, and under different circumstances pertaining to disease. At certain points, the element of impulsion may be eliminated, leaving the valvular element alone present. The element of impulsion predominates and drowns the valvular ele- ment, often on auscultation over the apex. It predominates, as a rule, over the body of the heart. At the base of the heart the valvular element frequently predominates. At the left border of the heart, over the left nipple, the valvular element predominates, and, on carrying the stethoscope to the left of this point for a greater or less distance, the element of impulsion is eliminated, and the valvular element remains, leaving the sound as purely valvular in quality and as short as the second sound. The valvular element predominates generally at the right border of the heart and at all the points removed from the pr^ecordial region where the first sound is appreciable. These facts, established by the clinical study of the heart-sounds in health, show that, although the element of impulsion predominates over the apex and body, the valvular element alone is much diffused beyond the limits of the organ,
' Discussion of this opinion, respecting tlie mechanism of the element of impul- sion of the first sound, is waived in this work. The reader is referred to the author's prize essay on the clinical study of the heart-sounds for the grounds on which the opinion is entertained, I will simply add here that the experiment of placing Cammann's stethoscope over the naked heart, when exposed in a living animal, seems to me sufficient to disprove the hypothesis that muscular contrac- tion furnishes an element of the first sound. The first sound in this experiment is intensely valvular. This sound sometimes has a similar intense valvular quality, in cases of great functional excitement of the organ, when the stethoscope is applied on the chest over the point of apex-beat, the element of impulsion heing, from some cause, wanting.
62 ENLARGEMENT OF THE HEART.
The valvular element is less intense than the second sound, the latter being often heard in situations to which the former is not transmitted, viz., on the lateral surfaces of the chest, in the right infra-clavicular region, and over the back.
The valvular element of the first sound, as stated already, is due to the action of the mitral and tricuspid valves. Is the sound emanating from each of these valves ever distinguishable from the other ? Clinical observation warrants an affirmative answer to this inquiry. Over the inferior border of the heart, near the xiphoid cartilage, this element frequently differs in pitch from the same element when heard in the same person at or without the left nipple. This may be considered as sufficient to render it at least highly probable that the source of the sound in the latter situation is at the mitral, and in the former situation at the tricuspid valves. A striking point of disparity between the first and second sound of the heart relates to the extent of variation in intensity in differ- ent persons, and in the same person under different circumstances within the limits of health, as well as in connection with disease. The first sound varies considerably in intensity according to the energy with which the heart contracts, and according to the pos- ture assumed ; it is often feeble when the person lies on the back as compared with intensity in the sitting posture, or lying on the left side. The second sound, on the other hand, undergoes little change in intensity under these and other circumstances, irrespective of morbid conditions. The variation to which the first sound is liable relates chiefly to the element of impulsion. The valvular element, like the second sound of the heart, is not subject to much variation in intensity, exclusive of disease.
The relatively greater duration of the first sound of the heart, as compared with the second sound, depends on the element of impul- sion. In proportion as this element is predominant is the sound prolonged ; and, on the other hand, whenever this element i*s eliminated, the first sound is no longer than the second. The interval between the first and second sound is determined by the length of the first sound. This interval is shortened in proportion as the first sound is prolonged, and it is lengthened in proportion as the element of impulsion of the first sound is impaired or eliminated.
The foregoing brief account of the heart-sounds in health em- braces, as concisely as possible, the more important of the conclu-
HEAET-SOUNDS IN HYPEETROPHY. 63
sions deduced from the results of the analysis of the phenomena obtained by auscultation in the examination of twenty-five persons presumed to be entirely free from disease, the phenomena being carefully noted at the time of the examination. For a fuller account of these results, the reader is referred to the publication already alluded to. It remains now to notice the modifications of the heart-sounds observed in connection with hypertrophy of the heart. The modifications significant of hypertrophy, difl'er mate- rially from those which pertain to dilatation. The former relate to the present subject. The latter will be noticed in another section in connection with enlargement by dilatation.
Hypertrophy of the left ventricle tends to exaggerate the element of impulsion of the first or systolic sound so long as the muscular power of the heart remains unimpaired. The impulsive movements of the apex against the walls of the chest, ccetens paribus, are pro- portionate to the hypertrophy of this ventricle. Exceptions to this rule occur when the form of the organ is so changed that the apex ceases to come into contact with the thoracic walls, or when, owingr to muscular weakness, the impulsive movements are diminished instead of being increased. All observers have remarked that in cases of hypertrophy, while the muscular energy of the heart is proportionate to its increased bulk, the first sound is notably dull and prolonged. The dulness and prolongation of this sound, as compared with the second, in health, are due to the element of impulsion. It is, therefore, quite intelligible that when the impul- sive movements are increased, the effects on this sound are abnor- mal dulness and prolongation, as well as exaggerated intensity. Mere exaggeration of this sound is by no means in itself significant of hypertrophy. Increased muscular action of the heart, as in some instances of functional disorder, renders the sound abnormally intense, so that it is sometimes appreciable at a distance from the chest, and painfully perceived by the patient. Both elements of the sound, under these circumstances, are exaggerated. This is also true in cases of pure hypertrophy, i. e., uncomplicated with valvular lesions ; but in hypertrophy the element of impulsion is relatively more exaggerated than the valvular element, and hence, when the dulness and prolongation are marked, as well as the increased intensity, the modification becomes significant of this affection. Modifications affecting the valvular element of the first sound are of importance chiefly in connection with the diagnosis of
6-1: ENLARGEMENT OF THE HEART.
valvular lesions. The modifications significant of hypertrophy relate more especially to the element of impulsion.^
Modifications of the second or diastolic sound, incident to hyper- trophy, may affect the aortic and the pulmonary sound separately or combined. The pulmonary and the aortic sound are in relation respectively to the right and left ventricle. The expansion of the semilunar valves succeeding the ventricular systole is due, in a great measure at least, to the systolic contraction of the ventricles. The column of blood propelled from the ventricles dilates the aorta and pulmonary artery, and the recoil due to the elasticity of the coats of these vessels during the ventricular diastole gives rise to the expansion of the valves, which occasions the second sound. This is the explanation now generally received of the mode in which the expansion of the valves is produced. Whether another agency be not involved in the production of the second sound, viz., an active diastolic expansion of the ventricles, is a matter of ques- tion. The force derived from the elasticity of the arteries, if not the sole agency, is, at all events, the most important in causing the expansion of the valves. This force, it is obvious, other things being equal, is proportionate to the power of the ventricular sys- tole. The dilation of the aorta and pulmonary artery is greater the more powerful the contractions of the ventricles, and the re- bound of the arterial coats is stronger the more the vessels have been dilated. Hence, the intensity of the second sound of the heart represents the power of the systolic contractions of the ventricles ; and the aortic and the pulmonary sound respectively represent, in this respect, the left and the right ventricle. The two ventricles, as has been seen, mtiy become enlarged by hypertrophy separately, as well as conjointly ; and when both are affected the enlargement of one generally predominates over that of the other. It might, therefore, be expected, and clinical observation shows that an abnormal intensity of the aortic and the pulmonary sound sepa-
' My clinical observations have led me to regard exaggeration of the tricuspid portion of the valvular element of the first sound as evidence, in some cases, of hypertrophy of the right ventricle. To determine the fact of its exaggeration, the valvular element of the first sound is to he compared at the inferior boundary of the heart, near the xiphoid cartilage, with this element at the left border of the heart at or without the left nipple. In health, this element of the first sound is notably more feeble in the former than in the latter situation. If the valvular sound be equally or more marked at the inferior boundary of the heart, provided the mitral valves are sound, it is evidence that hypertrophy of the right ventricle exists, if other signs of cardiac enlargement are at the same time present.
HEAET-SOUNDS IX HYPERTROPHY. 65
ratelj, may become a sign of hypertrophy affecting, in the one case, the left, and, in the other case, the right ventricle.
Hypertrophy of the left ventricle gives rise to exaggerated intensity of the aortic second sound, i. e., the sound having its maximum of intensity in the second intercostal space on the right side of the sternum, provided this effect be not prevented by attendant circumstances, which are of frequent occurrence. Lesions affecting the aortic valves, diminished elasticity of the aorta from disease of its coats, contraction at the mitral orifice, or mitral re- gurgitation, both lessening the column of blood propelled by the ventricle into the aorta, are circumstances which obviously stand in the way of an abnormal increase of the aortic second sound proportionate to the augmented power of the ventricle. Hyper- trophy of the left ventricle is seldom altogether devoid of these circumstances. In point of fact, it is only in the rare instances of uncomplicated hypertrophy of this ventricle that the aortic second sound is notably exaggerated. As a physical sign, therefore, it has very little value.
Hypertrophy of the right ventricle, on the other hand, is seldom associated with circumstances preventing its effect on the pulmonary second sound, ?*. e., the sound as heard in the second intercostal space on the left side of the sternum. Lesions of the semilunar valves of the pulmonary artery, and of the tricuspid valves, are of extremely infrequent occurrence. Exaggerated intensity of the pulmonary second sound, therefore, is highly significant of hyper- trophy of this ventricle. This effect is especially marked if, in conjunction with increased power of the ventricular contraction, there exists congestion of the pulmonary vessels involving obstruc- tion to the free passage of blood through the lungs. The resistance which the column of blood propelled into the pulmonary artery meets with, induces a greater dilation of this artery during the ventricular systole, and, consequently, a stronger recoil after the systole, giving rise to a louder pulmonary second sound. Pulmo- nary congestion, often due to mitral contraction or regurgitation, generally co-exists with hypertrophy of the right ventricle, and stands to the latter in the relation of causation. In estimating the amount of exaggerated intensity of the pulmonary second sound, it is to be compared with the aortic second sound in the same intercostal space on the right side of the sternum. In making this comparison, it is to be borne in mind that lesions affecting the mitral orifice (contraction, or regurgitation, or both), which are
0
QQ ENLARGEMENT OF THE HEART.
often associated with hypertrophy of the right ventricle, involve diminished intensity of the aortic sound by lessening the amount of blood propelled by the contraction of the left ventricle into the aorta. Under these circumstances, the pulmonary second sound may be more intense than the aortic, when its actual intensity is not augmented. Exaggeration of the pulmonary second sound occurring in connection with the mitral lesions just named, will be again noticed in treating of these lesions. It is also to be borne in mind that in mere functional excitement of the heart, both the pulmonary and aortic second sound acquire an abnormal intensity. Under these circumstances, the second sound, in both situations, is alike exaggerated. Abnormal increase of the intensity of the sound emanating from either the aorta or pulmonary artery, is more signi- ficant of hypertrophy than when the sound from both of these sources is alike augmented. But with respect to the second, as well as the first sound, abnormal increase of intensity is to be considered as a sign of hjq^ertrophy only when other physical signs of enlargement of the heart are at the same time present. Another point is not to be lost sight of, viz : In the progress of hypertrophy, a period arrives when the muscular power of the heart becomes abnormally weak, notwithstanding the increased thickness of the muscular walls. When this period arrives, the heart-sounds are feeble in proportion to the weakness of the ventricular contractions. Enlargement of the heart gives rise to certain abnormal changes as regards the respiratory murmur and vocal resonance within the prsecordia, which possess some importance as physical signs. In health, the respiratory murmur may, or may not be perceived within the superficial cardiac region during tranquil breathing ; but it is generally heard everywhere within the priecordia when the breathing is forced. In cases of enlargement, however, in which the area of the superficial cardiac region is increased, not only is the murmur in tranquil breathing inappreciable, but it may not be discoverable although the breathing be forced. This is corrobora- tive of the more reliable evidence of enlargement afforded by per- cussion and palpation. The vocal resonance, in health, when more or less marked over the left side of the chest, is either extinct or notably diminished within the prascordial region. The boundaries of the heart may often be as accurately defined by auscultating the voice as by percussion; and, in conjunction with the latter method, the former may be resorted to in determining the augmented space which the heart occupies in cases of enlargement.
SIGXS BY INSPECTION. 67
4. Enlargement of the prBecordia and abnormal movements, as deter- mined by inspection.
In healthy persons, free from spinal curvature and obvious de- formity of the chest, the prtecordial region and the corresponding section on the right side do not present any marked deviation from symmetry. On close comparison with the eye, frequently a slight disparity is perceived, one side projecting a little more than the other. Of the instances, according to my observations, in which this disparity is perceptible, the right and the left side are found to project in an equal proportion. Of twenty-five examinations of different persons in health, with well formed chests, and no spinal curvature ; in seven, no disparity was observable ; and in an equal number, viz., in nine, the right and the left side, respectively, were found to be slightly more prominent. Three of these persons were left handed. In one of these three persons, the right side was more prominent ; in another, the left side, and in one there was no disparity.'
Abnormal prominence of the preecordial region occurs in certain cases of enlargement of the heart. The prominence is considerable in some cases, when the heart is enlarged in early life. In a mod- erate amount, it is not uncommon in cases in which the affection is developed after adult age. Praecordial prominence, due to the accumulation of liquid within the pericardial sac, in cases of peri- carditis, may generally be distinguished from that due to enlarge- ment of the heart, by characters determinable by inspection, although the differential signs obtained by other methods of ex- ploration are more strongly marked. The shape of the praecordial projection is not the same in enlargement of the heart as in peri- carditis with effusion. In the latter it extends more in a vertical than in a transverse direction. In the former, the arching is wider, and does not extend much, if at all, above the normal situation of
' M. Woillez found, of 197 subjects in good health, and without spinal curva- ture, that in 47 only was the symmetry absolutely perfect. A projection of the left side, in front, either at, or above, or below the nipple, existed in the proportion of 26 per cent. An anterior projection of the right side existed in only two in- stances. The proportion of instances in which deviation from absolute symmetry existed in my comparatively few examinations, agree very nearly with those of M. Woillez. The proportion of instances in which prominence of the left side was noted is larger in my examinations, and the relative number of instances in which prominence of the right side was observed, is still greater.
68 ENLARGEMENT OF THE HEART,
the base of tlie heart. Priecordial prominence due to enlargement, if it exist in a notable degree, denotes both hypertrophy and dila- tation, because it is in this species of enlargement that the heart attains to a large size. The projection is very rarely, if ever, so great as in certain cases of chronic pericarditis. The intercostal depressions are not so uniformly abolished. Bulging of the inter- costal spaces, which may result from pericardial effusion, never occurs in cases of enlargement. Widening of the intercostal spaces does not take place to the same extent in cases of the latter as of the former. In enlargement, the apex-beat is generally seen and felt, while in pericarditis it is often suppressed ; and if appreciable in the latter affection, it is raised above its normal position, while in the former it is often lowered and carried to the left. Other points of distinction will be noticed in treating of pericarditis. It may be added here that the prominence dependent on enlargement is permanent and unchangeable, while that due to pericardial effu- sion is sometimes developed under the eyes of the practitioner, and, after variations at different times, may finally disappear and be followed by depression.
Movements of impulsion and retraction referable to the heart in cases of enlargement, which have been considered in connection with palpation, are, in general, appreciated by the eye as well as by the touch. Retractive movements may be ascertained by in- spection when they are not perceived by palpation. The retraction of the apex-beat is sometimes plainly seen, when an impulse can- not be felt. The alternate movements in different intercostal spaces, which were described as determined by palpation, are best ascertained by inspection. The applicability of this method of exploration to the study of the movements communicated by the heart to the thoracic walls, is to be borne in mind, but it is need- less to repeat in this connection the account of these movements, which has been already given.
5. Increased size of the chest as determined by mensuration.
The value of mensuration in cases of enlargement of the heart, consists in its giving exactitude to certain of the signs obtained by inspection. It is not essential to the development of data for diag- nosis.
As regards measurements of the healthy chest, with reference to the prcecordia, the following are the conclusions deduced from
SIGNS BY MENSURATION. 69
twenty-five examinations in which the circumference was measured with graduated inehistic tape, and the diametrical distance by means of callipers. Equality of the two sides of the chest, and a greater size of the left side, as regards circumference and antero- posterior diameter, do not alone constitute evidence of cardiac or other intra-thoracic disease. This statement holds good within certain limits ; in other words, greater size of the left than of the right side beyond half an inch, either by diametrical or circular measurement, points to the existence of disease. Diametrical measurement gives a larger number of instances in which the two sides are equal, than circular mfeasurement, the ratio being six to eleven. The right side was greater in eleven instances as measured by the tape, and in seven as measured by callipers, A greater size of the left side existed in an equal number of instances as deter- mined by the tape and callipers, viz., in five. In all of sixteen cases in which diametrical measurement showed greater size of either the right or left side, the same results had been previously obtained by inspection, with a single exception.
Thus, in confirming and giving greater exactitude to the results of inspection, as respects the size of the chest in cases of cardiac disease, diametrical is to be preferred to circular measurement.
The antero-posterior diameter of the chest at the prsecordia is increased in certain cases of enlargement of the heart. In deter- mining that it is due to cardiac disease, abnormal conditions refer- able to the lungs or pleura, increasing the size of the chest, are to be excluded by the absence of the signs denoting their existence ; and the abnormal increase of the diametrical dimension of the left side is referred to an abnormal condition of the heart, not alone by the exclusion of diseases affecting other intra-thoracic structures, but by concomitant signs of cardiac enlargement. The advantage of mensuration as already stated, is mainly in corroborating the evidence afforded by the eye, and in enabling the physician to de- termine with greater precision the amount of disparity between the two sides. In recording cases, it is more satisfactory to note the results of a comparison of the two sides in figures than to express them in terms which are somewhat indefinite; such as slight, moderate, great, etc. With reference simply to diagnosis in indi- vidual cases, inspection suffices without resorting to measurement.
The diagnosis in cases of enlargement of the heart and hyper- trophy must rest on the physical signs. The symptoms which
70 EXLARGEilEXT OF THE HEART.
have been mentioned (page 33) may point to these lesions, and afford corroborative evidence of their existence, but they are not adequate to lead to positive conclusions. So far as concerns en- largement, it is determinable with great ease and precision b}' means of physical signs in the vast majority of cases. To deter- mine Avhether hypertrophy or dilatation predominate is more difficult, but in most instances it is practicable with due knowledge and care. As res-ards these two forms of enlaro;ement. the differ- ential diagnosis will be considered under the head of enlargement by dilatation in an after part of this chapter. The signs involved in the diagnosis of enlargement and hypertrophy are fewer and more simple than would appear from the space devoted to the subject in this chapter. The subject would here require compara- tively brief consideration had it not been requisite, in this connec- tion, to introduce accounts of the phenomena obtained by physical exploration in health, as the point of departure for studying the phenomena of disease relating not alone to the diagnosis of the affections treated of in this chapter, but to those Avhich are to be subsequently considered. The greater part of the present section has been occupied with facts which belong to physiology rather than pathology. Having been here introduced, it will only be necessary to allude to them hereafter in treating of subjects as preliminary to which they are equally important. For the conve- nience of the reader, a recapitulation of the physical signs of enlargement and of hypertrophy is given in the summaries which follow.
SUMMARY OF THE PHYSICAL SIGN'S OF EXLAKGEMEXT OF THE HEART.
1. Percussion. — The area of the superficial cardiac region ex- tended beyond the range of healthy variation, especially in width. The degree of dulness within this area greater than in health, and the sense of resistance more marked. The limits of the deep cardiac region, in other words, the boundaries of the heart, gene- rally defined by careful percussion, the dimensions of the space which the heart occupies being thus ascertained with precision, and the form of the organ delineated on the chest. Enlargement of the right or left auricle sometimes determined by the extent of the area of dulness at tlie base of the heart on the right or left side of the sternum.
SUMMARY OF SIGNS OF EXLAEGEMENT. 71
2. Palpation. — The apex-beat removed to the left of its normal position, and often lowered. The area within which the apex-beat is felt, extended bejond the range of health. Abnormal impulses felt in two, three, and sometimes even four intercostal spaces ; the additional impulses either synchronous or alternating with the apex-beat, in some instances referable to the auricles, although due to the ventricular systole ; and, when felt in the epigastrium, due to the action of the right ventricle.
3. AuscuUation. — The respiratory murmur not appreciable within the superficial cardiac region in tranquil breathing, and sometimes wanting when the breathing is forced ; feeble over a larger area within the pr^ecordia than in health. The boundaries of the heart defined by abrupt cessation or notable diminution of vocal reso- nance, and the augmented space which the organ occupies, in this way determinable in corroboration of the evidence afforded by percussion.
4. Inspection. — Abnormal projection of the prascordial region in some cases; the projection considerable if the enlargement take place in early life. The movements of impulsion determined, which are also ascertained by palpation ; movements sometimes seen which are not perceptible to the touch, especially movements which commence by depression with the systole of the ventricles. Alternate movements of intercostal spaces often apparent to the eye, which are imperfectly ascertained by palpation.
5. Mensuration. — Prominence of the pri^cordia greater than the corresponding portion of the chest on the right side ; in some cases apparent on inspection, but determined with precision by diametri- cal measurement. Mensuration also employed in determining with accuracy the dimensions of the superficial and deep cardiac regions, the position of the apex-beat relatively to the nipple, the median line, etc.
SUMMARY OF PHYSICAL SIGNS DISTINCTIVE OF ENLARGEMENT BY HYPERTROPHY.
1. Palpation. — Abnormal force of the apex-beat, denoting not merely excited action of the heart, but augmented power of the systole of the left ventricle, the impulsion prolonged, sluggish, and strong. A strong impulse in the epigastrium in cases of hyper-
72 ENLARGEMENT OF THE HEART,
trophy of the right ventricle ; the impulsions sometimes commu- nicated to the lower part of the sternum, and extending more or less over the site of the liver. A strong, heaving movement of the ribs or the entire prcecordia, in distinction from the shock, more or less violent, due merely to augmented functional activity of the ventricles.
2. Auscultation. — Exaggeration of the aortic second sound, and especially of the element of impulsion of the first sound, in hyper- trophy of the left ventricle, rendering the first sound dull and pro- longed, as well as abnormally intense. Exaggerated intensity of the pulmonary second sound, in hypertrophy of the right ventricle, especially if associated with obstruction to the pulmonary circula- tion. Augmentation of the tricuspid valvular element of the first sound in some cases of hypertrophy of the right ventricle.
Treatment op Hypertrophy,
False notions of the pathology of hypertrophy have hitherto led to erroneous principles of treatment, which govern, still, the prac- tice of very many, if not most physicians. The object has been to devise the most effective means of diminishing the state of hyper- trophy, i. e., of reducing the size of the ventricular walls, and, if this be not practicable, of preventing, if possible, progressive in- crease of the muscular tissue. For this end, some years age, copious and repeated abstractions of blood were employed, in conjunction with low diet, after the plan of "Valsalva and Albertini, Italian physicians. This method was found to be pernicious, but, instead of being discarded, the same plan, not carried to the same extent, was recomm.ended by Hope, Bouillaud, and others, and has been generally pursued up to the present time. A better understanding of the pathological relations of hypertrophy leads to the conclusion that therapeutical measures designed to diminish or prevent it, are likely to do harm in so far as they have efficiency in promoting these ends. Considered in connection with the antecedent morbid conditions which give rise to it, conditions involving impediment to the circulation, hypertrophy, so far from being an evil, is an im- portant provision against the dangers incident to accumulation of blood within the cavities of the heart, and against the evils of dila- tation, the latter being much the more serious of the two forms of
TREATMENT OF HYPERTROPHY. 73
enlargement. In the great majority of cases, enlargement of the heart is the result of valvular lesions. These lesions often exist for a long time before they give rise to symptoms which lead the patient to suppose that he is affected with disease. When cases first come under the notice of the practitioner, it is evident that the enlargement has been going on for months or even years. The amount of enlargement, when the chest is for the first time examined, shows that it is not of recent production. We have seen that, as regards hypertrophy and dilatation, which are almost always com- bined, the former, as a rule, takes precedence in time. The hyper- trophy, in short, compensates, during a greater or less period, for the disturbance of the circulation caused by th6 valvular lesions ; and so long as the enlargement consists of this compensating in- crease of muscular structure, and consequently of muscular power, the patient experiences little or no inconvenience, provided nothing occurs, like anemia, for example, to weaken the force of the heart's action. It is when the hypertrophy has reached the limit of com- pensation, and dilatation has followed, that serious inconveniences, referable to the heart and circulation, begin to be felt. With this general view of the pathological character of hypertrophy, the in- dications for treatment may be embraced in three classes, viz : 1. To prevent or limit, as far as practicable, impediment to the circulation dependent on valvular lesions or other conditions, and giving rise to hypertrophy ; 2. To obviate, as far as possible, weakness of the heart, and a tendency to dilatation ; 3. To quiet undue excitement and irregular action of the heart.
The antecedent pathological conditions giving rise to cardiac enlargement, viz., valvular lesions, pulmonary emphysema, etc.', are not of a nature to admit of removal. The physician, however, can do something towards preventing or limiting the impediment to the circulation, which is the immediate effect of these conditions, and which is the intervening cause of enlargement. This indication is fulfilled by avoiding extrinsic causes which excite unduly the action of the heart, by measures designed to equalize the circulation, and by the judicious employment in some cases of bloodletting and other means of depletion. Excessive muscular exercise is objec- tionable, but, as will be seen presently, within certain limits it is not to be prohibited, but enjoined. Excesses in eating and in the use of stimulating drinks are to be avoided. ]\rental excitement belongs in the same category. The circulation is equalized by securing, as far as may be, for the different, and especially the
74 ENLARGEMEXT OF THE HEART.
remote parts of the body a proper proportion of blood, thus pre- venting its undue accumulation within the cavities of the heart. For this end, the surface of the body should be guarded against the influence of cold, and revulsive measures, such as warm and stimu- lating pediluvia, frequently resorted to if the circulation in the extremities be sluggish. Constipation, if it exist, claims appropriate remedies. Bloodletting is permissible when there exists over- repletion of the general vascular system, the object being, by lessening the mass of blood, to facilitate its circulation. This object should be clearly understood. It is easy to understand that if the vessels are abnormally full of blood, an irremediable impedi- ment to the circulation is likely to occasion greater accumulation in the heart and its cavities than when the mass of blood to be circulated does not exceed the normal amount. The existence of plethora furnishes the indication for bloodletting, and the removal of this state constitutes the limit to which it may with propriety be carried.'' Carried beyond this limit, the detraction of blood can hardly fail to be pernicious. It is to be borne in mind that blood- letting is not to be practised because hypertrophy exists, but because over-repletion of the vascular system, added to an existing permanent impediment to the circulation, increases the necessity, as it were, for the production of hypertrophy. Injudiciously prac- tised, bloodletting is injurious in proportion as it impoverishes the blood and weakens the muscular power of the heart. Eesorted to with reference to the object just stated, it is indicated in only a certain proportion of cases, and the abstraction of a large quantity of blood is very rarely, if ever, called for. The end for which bloodletting is employed may generally be fulfilled by other methods of depletion which involve less risk of doing harm. The use of saline laxatives and diuretics, conjoined with a somewhat restricted diet, and, more especially, with restriction in the quantity of fluid ingesta, will, in most instances, accomplish the object. These means are to be preferred on account of their being free from the evils attending the spoliative effects of bloodletting when employed injudiciously.
The inconveniences arising from hypertrophy are aggravated by
' It is assumed tliat the state of plethora, i. e., abnormal augmentation of the mass of blood, may exist, and also that when the mass of blood is diminished by bloodletting or other means, the vessels are not immediately refilled. The assump- tion of these points, in opposition to the speculative views of some, is believed by the author to be iu accordance with clinical observation.
TEEATMENT OF HYPERTEOPHY. 75
weakness of the heart. All observers have noticed the evils of coexistiug antemia. Impoverishment of the blood renders the heart irritable, easily excited into violent and irregular activit}', while its power of action is impaired. Alarming symptoms are sometimes induced under these circumstances, which are so entirely relieved by restoring the blood to its normal condition that patients imagine themselves completely cured. A patient, rendered highly ancemic by lactation, presented dyspnoea, palpitation, and oedema to such an extent that her condition seemed quite hopeless, but after weaning, the use of tonics, etc., she recovered apparently perfect health, so that, except for the physical signs of cardiac disease, the cure would have been considered complete. Two years afterwards she had apoplexy followed by hemiplegia, which terminated fatally. The combination of anaemia and enlargement of the heart is to be prevented, if possible ; and, if it exist, the anaemia, if possible, is to be removed by appropriate measures of medication, diet, and regimen. Irrespective of this condition of the blood, all agencies which tend to weaken unduly the force of the ventricular contractions are contra-indicated. In proportion to the weakness of the heart will be the tendency to dilatation rather than to hypertrophy. The latter is to be promoted, if this be necessary to prevent the former. So long as hypertroph}'- pre- dominates, the patient is comparatively safe. The inconveniences and dangers are greatly increased in proportion as dilatation suc- ceeds hypertrophy. It is an important object of treatment, there- fore, to obviate or retard the tendency to dilatation. With reference to this object, the diet should be nutritious — a substantial, solid diet, adapted to the formation of blood, rich in quality, but not in excess as regards quantity. Muscular exercise within certain limits is to be encouraged rather than repressed. In cases of cardiac disease attended with enlargement, I have been repeatedly struck with the fact that persons engaged in pursuits requiring considerable ph3^sical exertions, laborers, mechanics, or active men of business, continue to discharge their duties for a long time without much inconvenience, but fail rapidly so soon as they dis- continue their occupations. I am convinced that a certain amount of exercise is not only allowable, but positively beneficial by pro- moting the heart's vigor and retarding the passage from predomi- nant hypertrophy to predominant dilatation. It will doubtless seem at first strange to many readers that exercise is recommended in cases of hypertrophy, but, while violent exertions, which excite
76 ENLARGEMENT OF THE HEART.
unduly the action of the heart, are to be avoided, I am satisfied that moderate and even considerable muscular activity conduces to the "welfare of the patient.
At the time of writing I can call to mind a number of persons affected with hypertrophy complicated with valvular lesions, who, engaged in active occupations, and pursuing no medical treatment, would be amazed were they fully aware of their pathological con- dition. I cannot but think that were the nature and extent of the disease clearly explained to these persons, and great quietude enjoined, their chances for tolerable health for a considerable period would be materially impaired. Still less encouraging would be the prospect were they subjected to a course of diet and medica- tion tending to impoverish the blood, reduce the vital forces, and weaken the power of the heart. I cannot avoid the reflection that I have witnessed the injury inflicted by this course of management in not a few cases.
In cases of complicated hypertrophy, the heart is liable to be unduly excited, and irregular action take place, even when extrinsic causes are, as much as possible, avoided. In other words, func- tional disorder, or palpitation, may be superadded to the organic affections. This is not only a source of inconvenience, but there is reason to believe that the effect is unfavorable as regards the permanent condition of the heart. To quiet undue excitement and irregular action of the heart, is therefore an object of treatment. Certain remedies may be employed with advantage for this object. Digitalis is a valuable remedy, frequently exerting a sedative effect upon the heart, without lessening the power of its action. Under its judicious use, the ventricular contractions often become less frequent, more regular, and apparently more complete. Care is to be taken not to give it in doses sufficient to reduce the pulse much below its normal frequency, and with due care it may be con- tinued for some time without risk of unpleasant consequences. Bouillaud claims that its endermic application, blistering a small space, and sprinkling daily several grains on the blistered surface denuded of its cuticle, possesses great advantages. Others, how- ever, have not observed that the beneficial effects are more marked when this method is employed, than when it is administered in- ternally. It is possible that the same effects may be obtained from the use of the veratrum viride, introduced by Dr. Norwood. Aconite is highly extolled by Dr. Walshe. He gives this the pre- ference over any other remedy in meeting the indication under
ENLARGEMENT BY DILATATION. 77
consideration. Belladonna is useful in some cases. A belladonna plaster, worn over the prascordia, lias seemed to me to exert a decided effect in tranquillizing the heart. The sedative effect of hydrocyanic acid is useful in some cases.
In these remarks on the treatment of hypertrophy, I have not discussed the feasibility of diminishing the abnormal growth of the muscular walls of the heart, a subject concerning which different writers have held opposite opinions. The views of the pathological character of hypertrophy which have been presented, divest this subject of the practical importance which has heretofore been at- tached to it.
ENLARGEMENT BY DILATATION,
Under this head are embraced, in addition to the rare instances of pure or simple dilatation, ?'. e,, cases in which the capacity of the cavities is increased, and the walls attenuated, all cases in which the relative amount of dilatation exceeds that of hypertrophy. Of the two kinds of enlargement, this is by far the most frequently found after death in the cases in which organic disease of the heart proves fatal. In the instances in which the heart attains to a very large size, dilatation almost invariably preponderates. The cases in which the organ, from its immensely augmented bulk, resembles a bullock's heart [cor hovinum), are those in which there exists a great amount of hypertrophy, together with a still larger amount of dilatation. The degree of dilatation varies greatly in different cases, and the lesser amount of hj^pertrophy combined with it, is also vari- able. The preponderance of the dilatation, when the heart is ex- amined after death, is generally sufficiently evident on inspection. The abnormal increase in the dimensions of the organ exceeds that of the weight. The ventricular walls collapse, and the organ, resting on its posterior surface, is flattened, instead of preserving a globular form, as when hypertrophy predominates. The greater increase in width than in length, is marked in proportion to the preponderance of dilatation. Owing to this, the organ becomes wedge-shaped, and sometimes presents nearly a square form.
The pathological process involved in dilatation is quite different from that which occasions hypertrophy. In the latter instance, the
78 EXLARGEilEXT OF THE HEART.
process is vital, in the former, mechanical. Hypertrophy is a con- sequence of over-nutrition ; dilatation is the result of the 3nelcling of the walls of the heart to a distending force. The condition, however, which stands immediately in a causative relation to both processes is the same, viz., undue accumulation of blood within the cavities of the heart; hence it is that both processes take place either conjointly or in succession, and that hypertrophy and dila- tation are almost invariably associated. Dilatation, thus, not less than hypertrophy, depends on antecedent affections which occasion impediment to the circulation through the vessels or the orifices of the heart, leading to over-accumulation of blood within the centres. These antecedent affections, with which the dilatation is complicated, are the same as in cases of predominant hypertrophy ; and the several compartments of the heart become affected singly and in succession, as in the latter form of enlargement. It is not neces- sary, therefore, in this connection, to consider the dilatation of these compartments, respectively, in relation to the particular lesions of the valves and orifices and vessels on which dilatation and hypertrophy alike depend. Moreover, both dilatation and hypertrophy of the different divisions of the heart will be referred to hereafter in treating of valvular lesions. It will suffice to inquire into the circumstances which determine the occurrence of dilatation in the place of, or, as is generally the case, in addition to hyper- trophy.'
The first effect of an undue accumulation of blood in the cavities of the heart, continued for a sufficient period, is increased muscular action and consequent hj^pertrophy in the great majority of cases. The hypertrophy is more or less progressive, but it has its limit. The abnormal growth of the muscular tissue ceases at a certain point. But the morbid conditions inducing over-repletion of the cavities, still remain, impeding more and more the circulation. The compensating increase of the muscular tissue no longer taking place, the walls of the cavities yield to the mechanical force of distension and the progressive enlargement from this time onward is due to dilatation. The limit of hypertrophic enlargement varies in different persons. If it do not cease till the muscular walls attain to a great thickness, and life continue for a long period afterward, the dilatation finally predominates, and the result is an
' Of 209 cases of dilatation analyzed by Dr. T. K. Chambers (Decennium Patho- logicum), in 69 the valves were free from disease, leaving 140 cases of complicated dilatation.
EXLARGEMENT BY DILATATION. 79
enormous enlargement of the heart, a cor bovinum. But dilatatioa may commence after moderate or slight hypertrophy has taken place ; in other words, the hypertrophy ceases after a smaller amount of muscular growth, and dilatation commences. Dilatation may even commence without any previous hypertroph}-, and the result is, then, enlargement with attenuated walls, or simple dilatation, a rare variety of cardiac enlargement. The occurrence of dilatation is determined by the state of the muscular walls. Functional debility of the organ, and, still more, changes in the muscular fibres, prevent that vigorous activity which induces abnormal growth, and yielding of the walls takes place early in proportion as the vital power of resistance is impaired. Anaemia, the feeble- ness consequent on pericarditis and adherent pericardium, fatty degeneration, softening, and any changes which compromise the muscular power of the organ, tend to abridge hypertrophy and favor dilatation. The latter will therefore predominate in propor- tion as the condition of the walls is such that they early and readily yield to the distension caused by the accumulation of blood within the cavities. After this brief consideration of the circumstances determining the occurrence of dilatation, in addition to the inci- dental remarks already made under the head of enlargement by hypertrophy, the reader will be able to trace the relations of dila- tation affecting the different cavities of the heart to lesions of the mitral and aortic orifices, involving either obstruction or reouroi- tation, or both ; and to obstructions affecting the pulmonary and systemic arterial systems at situations more or less remote from the heart, without a recapitulation of the account already given in connection with hypertrophy. The inquiry arises. Does not the heart in some instances become dilated in consequence of inherent weakness, no antecedent affections existing to occasion impediment to the circulation? It is probable that this sometimes occurs as an effect of fatty degeneration, pericardial adhesions, atrophy or soft- ening of the muscular fibres, etc. Examples are found of dilatation associated with these structural changes, and without other obvious sources of impediment to the circulation. These changes may take place subsequent to dilatation, but it is reasonable to suppose that in some instances they precede and give rise to it. Clinical ob- servation, however, furnishes no evidence that functional weakness alone leads to dilatation, irrespective of structural changes of the walls of the heart, or lesions of some kind which occasion impedi- ment to the circulation. Dr. T. K. Chambers has sugo-ested that
so ein-argement of the heart.
general obesity may prove a cause of dilatation, in consequence of the " increased area of capillaries through which, the blood has to be propelled in fat people.'"
Symptoms and Pathological Effects of Dilatation.
The symptoms due to dilatation, like those of hypertrophy, are generally so involved with those incident to valvular or other con- comitant lesions, that it is difficult, if not impossible, to disconnect them entirely from the latter in individual cases. The materials for the clinical history of simple, uncomplicated dilatation (exclud- ing not only valvular lesions and obstructive affections more or less removed from the heart, but also diseases of the pericardium and structural changes of the cardiac walls), are yet to be collected. An approximation, however, may be made toward the symptoma- tology of this form of enlargement, by contrasting cases of com- plicated hypertrophy with those of complicated dilatation. In proportion as dilatation predominates, the power of the heart is impaired. The symptoms distinctive of dilatation, in fact, proceed from feebleness and incompleteness of the heart's action. The action of the heart is often irregular, as represented by irregularity of the pulse and of the apex-beats. Both are abnormally feeble. The pulse may be unequal as well as irregular, but it is difficult to say to what extent this may be owing to concomitant valvular affections. The patient experiences more or less uneasiness and undefinable distress referable to the prrecordia, but he is not con- scious of that powerful action of the heart which characterizes hypertroph3^ Visible throbbing of the superficial arteries is not perceived. The extremities and surface of the body are cool. Lividity may be apparent on the prolabia, the tongue, face, and extremities. The veins may be distended. These symptoms are more or less marked in proportion as the dilatation affects the left ventricle. Dyspnoea will be prominent in proportion as the right ventricle is the seat of dilatation. The recumbent position, with the head low, may be insupportable, and in an advanced stage, the suffering from defective hoematosis may amount to orthopnoea. Occurring in paroxysms, this difficulty of respiration constitutes the affection called cardiac asthma. Exercise, and mental excite-
' Bellingliam on Diseases of the Heart, Part 2. Dublin, 1857, p. 465.
SYMPTOMS OF DILATATIO' 81
meut exasperate the symptoms, particularly those referable to the respiration. More or less cough and expectoration are usually present. The abdominal viscera, as -well as the lungs, are in a state of passive congestion. Owing to this state, the liver is often more or less enlarged permanently, and may be found to augment rapidly in size when, from any cause, the circulation is temporarily embarrassed in an unusual degree, resuming its former dimensions when the paroxysm ends and the heart recovers its habitual strength.' The digestive functions are weakened, but nutrition may be sufficiently active; patients do not always emaciate. The urine is not abundant, and may be found slightly albuminous, which is due to renal congestion and not necessarily indicative of structural disease of the kidneys. Granular degeneration, or Bright's disease, is, however, associated, in a certain proportion of cases, with dilatation as with hypertrophy. Finally, oedema occurs, first, manifested in the lower extremities, thence extending over the body, and effusion into the serous cavities succeeds, constituting general dropsy.
This is an enumeration of the more important of the symptoms belonging to cases of enlargement in which dilatation predominates, but it is to be borne in mind that, in general, valvular or other lesions co-exist, which, after inducing more or less hypertrophy in the great majority of cases, have at length led to the superinduction of dilatation ; and, under these circumstances, it is difficult to say to what extent the symptoms distinctive of this stage of the disease may not be due to the causes of the dilatation, in other words, to the degree and duration of the concomitant lesions. It can hardly be doubted that considerable importance is to be attached to the dilatation in the production of the symptomatic phenomena which have been mentioned.
The pathological effects of dilatation are in a great measure em- braced in the foregoing account of the symptoms. The dilatation is the result of weakness of the cardiac walls, together with an accumulation of blood within the cavities; and, on the other hand, it is the cause of further diminution of the power of the heart's action, and consequent over-repletion. It involves, therefore, an intrinsic tendency to increase. The evils incident to enlargement are mostly referable to dilatation. Little or no inconvenience is felt so long as the heart is hypertrophied, and the capacity of its
' Stokes on the Heart and Aorta.
82 ENLAKGEMENT OF THE HEART.
cavities not increased. But in proportion as the latter takes place, the quantity of blood to be propelled from the cavities is greater, and the ability of the muscular walls to contract sufficiently for its propulsion is lessened; hence, inadequacy of the motive power of the central organ to carry on the circulation. This inadequacy increases in more than an arithmetical ratio as the dilatation pro- gresses. The immediate effect on the vascular system is passive congestion, arising not alone from the defective propelling power of the heart, but from the obstacle presented to the return of blood to this organ by the accumulation within its cavities. The ulterior effects dependent on congestion are, embarrassment of the functions of the important organs of the body, serous transudation or dropsy, and, occasionally, hemorrhage. An occasional effect of great dila- tation conjoined with extreme feebleness of the heart's action, is the formation of coagula within the cavities. There is reason to believe that in some instances in which the accumulation is exces- sive, and the contraction of the walls extremely feeble, the blood coagulates during life, and proves the immediate cause of a fatal termination. The formation of coagula in the heart during life will receive distinct consideration in a subsequent chapter.
Physical Signs and Diagnosis or Dilatation.
The physical signs of enlargement of the heart have been already fully considered. The signs distinctive of dilatation are now to be noticed. The several methods of exploration which furnish evi- dence of enlargement, supply certain indications pointing to dila- tation in distinction from hypertrophy. The indications derived from percussion relate to the form of the area of deep dulness. If the boundaries of the heart are delineated on the chest by careful percussion, the transverse dimensions of the area preponderates over the vertical, in proportion as the dilatation predominates over hypertrophy. This corresponds to the difference as regards the form of the heart, which has been mentioned. The outline which the heart presents is wedge-shaped or nearly square if the dilata- tion be excessive. Palpation furnishes negative characters more readily available and striking. The sluggish, powerful apex-beat of hypertrophy is wanting ; also the elevation of the ribs and the heaving of the prsecordia. The impulse of the apex is feeble, and may be suppressed. The movements of the organ, owing to the
PHYSICAL SIGNS OF DILATATION". . 83
extended space in which it is in contact with the thoracic walls, are sometimes obscurely felt, and oftener visible in two, three, and even four intercostal spaces, which together present an appearance of fluctuation, or, as called by Dr. AValshe, quasi undulation. In some cases in which the thoracic walls are thin, and the intercostal spaces wide, the heart, as has been remarked, seems to be almost exposed to the vision and touch." Auscultation furnishes certain distinctive points pertaining to the heart sounds. Both sounds are feeble in comparison with their augmented intensity in cases of hypertrophy, but the first sound is disproportionately weakened. The first sound is still more altered in character ; it becomes short and valvular, resembling in these respects the second sound. The latter alteration, although distinctive of dilatation, as contrasted with hypertrophy, is not peculiar to the former, and its true ex- planation has not been understood. It is due to the absence of the element of impulsion in the first sound. This element is defi- cient or wanting whenever the left ventricle lacks the muscular power necessary for its production. In hypertrophy this element is exa2;2ferated owing to the increased force of the ventricular con- tractions ; and in dilatation it is feeble or absent owing to the feebleness which at the same time render the apex-beat weak or inappreciable. But this element is also impaired or eliminated when, from other causes than dilatation, the muscular power of the heart is weakened. The intensity of the first sound is diminished disproportionately to that of the second sound, and it is also short and valvular like the second sound, in cases of fatty degeneration, softening in typhus fever, and even of hypertrophy, when the power of the ventricular walls is greatly reduced. An adventitious sound or murmur is said to accompany the first or systolic sound in some instances of dilatation not complicated with valvular lesions. As a rule, a murmur is not present unless the latter coexist, or the blood have undergone those abnormal changes which occasion a murmur without any organic afi'ection of the heart. This point will be noticed in treating of murmurs in connection with valvular lesions. Inspection shows in certain cases the quasi-undulatory movements within the prsecordia which have been mentioned as also determinable by palpation. They are better perceived by the eye than by the touch. Inspection and mensuration may show an abnormal prominence of the prsecordia. In the rare cases of dila-
' Racle, op. cit.
84 ENLARGEMENT OF THE HEART,
tation with attenuated walls, it may be true that enlargement of the prsecordia never occurs. This is not true, however, of all the cases in which dilatation predominates over hypertrophy. With- out discussing the question whether enlargement by dilatation as well as by hypertrophy may not give rise to prsecordial projection, this result may be produced by the hypertrophy before the super- vention of dilatation which subsequently becomes predominant. Absence of prsecordial prominence does not then belong among the negative signs of enlargement by dilatation.
Inlhe diagnosis of enlargement by dilatation, assuming the fact of enlargement to be ascertained, symptoms (as distinguished from signs) have considerable weight. Passive congestions, lividity, feeble pulse, and dropsical effusion, in fact, constitute evidence almost, if not quite, conclusive. The obstruction due to valvular lesions so generally associated with enlargement, it is true, contri- bute towards the production of these symptoms ; but, as will be seen when valvular lesions are considered, the obstruction due to these rarely, if ever, give rise to the effects just mentioned until dilatation of the cavities of the heart has taken place. With the aid of the physical signs, the discrimination between predominant dilatation and predominant hypertrophy may generally be made with confidence. The cases in which there is room for .doubt are those of hypertrophy when, from any cause, the muscular power of the heart is notably weakened. The differential diagnosis is of importance with reference to prognosis and treatment. The pros- pect of life and tolerable health is less in proportion as dilatation predominates, and the management involves attention to incidental events, which do not occur so long as hypertrophy preponderates. For the convenience of comparison with the physical signs distinct- ive of hypertrophy (see page 71), the signs distinctive of dilatation are embraced in the following summary.
SUMMARY OF THE PHYSICAL SIGNS DISTINCTIVE OF ENLARGEMENT BY DILATATION.
1. Percussion. — The transverse dimensions of the space occupied by the heart greatly exceeding the vertical, the form of this space corresponding to the wedge-like or square form of the organ when the dilatation is excessive.
2. Palpation. — The apex-beat devoid of abnormal force and in some instances suppressed. Absence of heaving movement of the ribs and prsecordia.
TREATMENT OF DILATATION. 85
3. Auscultation. — The element of impulsion of the first sound deficient or absent, and the sound short and valvular, in these respects resembling the second sound.
Treatment op Dilatation.
With certain qualifications, the indications for the treatment of dilatation are the same as in cases of predominant hypertrophy. The impediment to the circulation dependent on the lesions which coexist in the great majority of cases cannot be removed, but the effects may be mitigated by avoiding extrinsic causes which excite unduly the action of the heart. Bloodletting is called for much, more rarely, and is to be employed with greater circumspection than when hypertrophy preponderates. Limiting the attention to the diminution of the mass of blood, it might seem that this mea- sure would fulfil an important indication. But it is to be con- sidered that bloodletting impoverishes the blood by its spoliative effects, and the secondary consequences are weakness and irrita- bility of the muscular structure of the heart. These consequences are hurtful to an extent greatly overbalancing the advantage of temporarily diminishing the quantity of blood to be circulated. Before resorting to this therapeutical measure, the physician should be satisfied not only that the impediment is aggravated by an over- plus of the mass of blood, but that the organized elements, viz., the corpuscles, which are disproportionately diminished by bloodletting, are not already deficient. No advantage to be derived from this measure can compensate for the evils of anaemia. Bearing in mind the immediate effects of bloodletting on the composition of the blood, and the secondary effects, due to impoverished blood, on the muscular structure, the cases in which it is called for seldom, if ever, occur. These remarks will, measurably, but not nearly to the same extent, apply to other methods of depletion, viz., saline pur- gatives and diuretics. Perhaps it may be said that in cases of dilatation the latter methods should be employed to the entire exclusion of bloodletting. Excessive muscular exercise, mental excitement, and other extrinsic causes exciting unduly the action of the heart, are to be avoided. Warmth of the external surface, and revulsive measures to attract blood to the extremities, are indicated oftener and more strongly in cases of dilatation than in cases of hypertrophy.
86 ENLARGEMENT OF THE HEART.
The measures which, in hypertrophy are pursued in order to prevent dilatation, are not less indicated when the latter exists. The great end in the management is to increase the muscular power of the heart. For this end, the diet should be as highly nutritious as possible, and the quantity of liquid ingesta as small as is compatible with comfort. In the arrangement of diet, the state of the digestive organs is to be consulted. Imperfect or labored digestion involves excited action of the heart, and is to be carefully avoided. When indigestion exists, palliative remedies are to be prescribed ; and remedies to improve the digestive function, viz., tonics and the judicious use of stimulants, constitute an important part of the treatment. Preparations of iron are especially indicated if there be anaemia. Constipation is to be prevented. Exercise, within certain limits, is to be enjoined. The injury arising from excessive muscular exertion has been referred to; but an extreme of quietude is not less hurtful, IIow is the judicious mean to be determined? The experience of the patient must be the guide. An amount or kind of exercise which excites unduly the action of the heart or occasions dyspnoea is to be abstained from ; but exer- cise short of these effects will be useful. Patients who follow avocations which involve manual labor will, in general, do better to pursue their callings, observing the precaution just mentioned, than to relinquish all occupation. The necessity for an undue amount of labor in order to obtain a livelihood is a calamity for persons affected with cardiac disease ; but a condition in life in which there is no other motive for exertion than the attainment of health is sometimes equally calamitous. Patients of the latter class should be encouraged to engage in sports which afford the requisite exercise, and, at the same time, interest the mind, such as shooting, fishing, and travelling. An advantage of no small account, inci- dental to pursuits which involve both exercise and mental occupa- tion, accrues from the diversion of mind and cheerfulness which they promote. Depression and gloomy forebodings are to be obviated as far as possible, and with a view to this, as much encouragement should be given as the nature of the case will permit. In a large proportion of the cases which the physician meets with in practice, he may conscientiously encourage hopes, not of cure, but of tolerable health for an indefinite period. The common notion that disease of heart generally ends in sudden death may be removed by positive assurances of its falsity.
Eemedies to allay undue excitement and irregularity of the
TEEATMENT OF DILATATION. 87
heart's action are indicated in cases of dilatation, as well as in cases of hypertrophy. The same remedies are indicated in both forms of enlargement ; but they are to be employed with more caution in the former than in the latter. The danger of weakening or retarding too much the muscular action of the heart is far greater in cases of dilatation. Anodynes, digitalis, aconite, etc., are serviceable, but must not be pushed beyond the effect of tranquillizing the action of the heart, incurring risk of weakening the muscular power of the organ.
The paroxysms of dyspnoea or orthopnoea, sometimes the source of great distress in cases of dilatation, are to be palliated by anti- spasmodic remedies and revulsive applications. Of the former, the ethers, and of the latter, sinapisms, dry cupping, and stimulating pediluvia are the most efficient.
The treatment of dropsy dependent on cardiac disease is deferred till after the consideration of valvular lesions.
CHAPTER II.
LESIONS, EXCLUSIVE OF ENLARGEMENT, AFFECT- ING THE WALLS OF THE HEART.
Atrophy, •witli diminished bulk of heart — Fatty growth and degeneration — Symptoms and pathological effects of fatty growth and degeneration — Physical signs and diagnosis of fatty growth and degeneration — Treatment of fatty growth and degeneration — Softening of the heart in typhus and typhoid fever and other affections — Treatment of softening of the heart — Induration of the heart — Cardiac aneurism — Rupture of the heart — Car- cinoma, tuberculosis, extravasation of blood and cysts.
Exclusive of enlargement, the heart is liable to various lesions affecting the walls of the organ, to some of which allusion has been already made, as standing in a causative relation to dilatation. Atrophy, with diminished bulk of the heart, is one of these ; fatty growth and degeneration constitute others ; other lesions are, soft- ening and induration, and in this category may be included aneu- rism of the heart and rupture. This chapter will be devoted to the consideration of these different organic affections, taken up in the order in which they have just been mentioned.
ATROPHY WITH DIMINISHED BULK OF THE HEART.
The muscular substance of the heart is sometimes diminished, the cavities not being enlarged, but, on the contrary, their capacity lessened. The organ is reduced in size below the normal limits. In the adult subject it may resemble in bulk the heart of a child. The weight corresponds to the diminution in size. This reduction in size and weight does not involve necessarily any notable change in the appearance of the organ in other respects, the only obvious deviation from the normal condition being the diminution in volume and in the thickness of the ventricular walls.
ATROPHY OF HEART. 89
This is undoubtedly to be considered as an organic affection of the heart, but it very rarely, if ever, occurs except in harmony, so to speak, with other morbid conditions, and under circumstances in which it neither occasions unpleasant consequences, nor claims attention in a therapeutical point of view. It is incidental to chronic diseases of long duration, characterized by gradual, pro- gressive emaciation. It is observed in some cases of pulmonary tuberculosis, and more especially in cases of carcinoma. It is said to follow, in some instances, pericardial adhesions and calcification of the coronary arteries ; but its dependence on these lesions does not appear to be established. It is observed, in some instances, in connection with a superabundance of fat on the exterior of the heart, and may be due, in these instances, as in cases of pericardial adhesions, to mechanical pressure of the organ continued for a long period. The conditions generally giving rise to it are diminution of the mass of blood, and of its nutritive materials — conditions in- volving diminished exertion of the muscular power of the organ. The heart wastes like other muscles when badly nourished and in- sufficiently exercised. But, under the circumstances, that is, in view of coexisting tuberculosis, or carcinoma, or some other affec- tion, which, like these, terminates fatally after slowly progressive emaciation, the cardiac atrophy, so far from being an evil, may perhaps belong among the conservative provisions of which the pathological history of even the most fatal forms of disease furnishes illustrations.
The symptoms of atrophy of the heart, it is sufficiently clear, must be those which denote feebleness of the circulation ; but in- asmuch as an enfeebled circulation due to other morbid conditions, precedes and gives rise to the atrophy, it must be difficult to decide to what extent the symptoms are dependent on the latter. Nor are the symptoms denoting feebleness of the circulation distinctive of this particular lesion of the heart. They are incident alike to dilatation, fatty degeneration, softening, &c. The physical signs are much more distinctive, and, in fact, suffice for the diagnosis. The boundaries of the superficial and deep cardiac regions are within the extreme limits of health; the apex-beat is indistinct or wanting, and the heart-sounds are abnormally feeble, and may be inappreciable. In a patient under observation at the time I am writing, a clear, vesicular resonance on percussion is elicited over the entire priecordia. The respiratory murmur is quite intense and normal over the whole prtecordial space, a fact which excludes
90 LESIONS AFFECTING THE AVALLS OF THE HEART.
emphysema of the portion of lung overlapping the heart. There is in this case no superficial cardiac region ; the anterior borders of the heart appear to meet. The left boundary of the deep cardiac region is sufficiently defined by the percussion-sound, and falls half an inch within the nipple. The apex-beat is not felt, and the heart- sounds are nowhere discoverable. There is evidently considerable atroph}'- in this case, yet there are no symptoms pointing to cardiac disease. The patient has for several years been affected with pul- monary tuberculosis, which is either non-progressive, or advancing very slowly.^
As already stated, atrophy of the heart does not call for medical treatment.
FATTY GROWTH AND DEGENERATION.
"With the undue accumulation of fat are connected lesions quite different in character and importance, according to the difference of situation in which the fat accumulates. More or less fat is gene- rally present in health on the outer surface of the heart after early infancy, especially on the right ventricle, at and near the base of the organ. It accumulates in this situation to an abnormal extent in some cases. A moderate amount of over-accumulation is fre- quently met with in post-mortem examinations, when there had been during life no symptoms of heart disease. If the quantity do not considerably exceed the normal average, although it must in some measure embarrass the movements of the organ, it does not occasion any serious results or appreciable inconvenience. When the accumulation is excessive, however, from its weight it leads to enfeebled muscular action and consequent weakness of the circula- tion. It may also favor dilatation if, from other causes, the blood accumulate unduly within the cavities of the heart. "Without these concurrent causes, it may induce atrophy with diminished size of the muscular portion of the heart. This variety of fatty heart occurs after the middle period of life, in persons who present evidence of an "adipose diaihesis,''^ viz : accumulation of fat in
' Case of Thos. Carr, Hospital Records, vol. xiii. page 87-
2 This term is borrowed from my friend, Prof. Gross. Elements of Pathological Anatomy, third edition, 1857. Dr. Bellingham also makes use of the term " fatty diathesis." Treatise on Heart, part ii., 1857.
FATTY GROWTH AND DEGENERATION. 91
different organs and beneath the integument, constituting corpu- lency. Not unfrequently, however, it occurs in persons who are not corpulent.' The heart is sometimes completely encased in a thick layer of adipose substance, which alters, in a marked degree, the external appearance and form of the organ. The volume of the heart is often increased not alone by the fatty deposit, but by more or less dilatation. Beneath the fatty layer the muscular sub- stance may not present any structural change. It is, however, generally unusually pale, and the texture softened.
The extension of fatty growth between the muscular fibres is followed by more serious consequences than when the deposit is limited to the surface of the organ. The pressure upon the fibres induces greater functional weakness, and, at length, atrophy. The power of the heart in propelling the currents of blood and in resist- ing the force of distension from accumulation within the cavities is proportionately lessened. Hence, feebleness of the circulation and proneness to dilatation in proportion to the amount of deposit in this situation. The deposit in this situation may be in the form of adipose vesicles and infiltrated oily matter.
Another variety, much more serious, and differing essentially in character, is that commonly known as fatty degeneration. The fat is deposited in the form of oil-globules within the sarcolemma. It replaces the muscular substance and constitutes another form of fatty atrophy. This variety may be associated with the preceding varieties of fatty heart, but it occurs independently of the latter. It affects more especially the left ventricle, while the varieties con- sisting of abnormal growth of the adipose vesicles are most abund- ant on and within the right ventricles. It may be pretty uniformly diffused over the left ventricle or the whole heart, but it is oftener confined to circumscribed patches or strips. The portions affected assume a yellowish or fawn color, which is somewhat characteristic, and if the heart be affected in disseminated patches it presents a mottled aspect. Examined with the microscope, the striae or trans- verse markings of the fibres are indistinct or wanting, and in place of the proper contents of the sarcolemma, it contains oil-globules in more or less abundance according to the amount of degeneration. It is evident that in proportion to the degree and extent of this
' Of 49 cases analyzed by Dr. T. K. Chambers (Decennium Pathologicum) , it was associated with general corpulence in 20, and occurred in persons not corpulent in 29. Vide Bellingham, op. cit. part ii.
92 LESIOXS AFFECTING THE WALLS OF THE HEART.
stractural change, the muscular power of the heart must be irre- coverably weakened. It is proportionately incapacitated to propel the blood with adequate force, and more readily yields to distension from the accumulation of blood. The portions of the organ which have undergone fatty degeneration are soft and friable, and it will be seen presently that when rupture of the heart takes place, it is owing generally to this structural change having occurred. Cases are reported in which apparently the greater part of the muscular substance had disappeared, the fibres preserving their outline, but containing fat instead of their proper anatomical elements. The auricles may be the seat of this fatty change, but much more rarely than the ventricles. For a fuller description of the gross and microscopical appearances presented in fatty degeneration, the reader is referred to works on morbid anatomy.^
The distinct pathological character of fatty degeneration, as compared with fatty growth upon the heart and between the muscular fibres, is a point of importance. The latter is, in fact, hypertrophy of the adipose tissue, while the former involves more properly an abnormal deposit. The term degeneration implies a conversion of the muscular substance into fat. That the mechan- ism of fatty degeneration does involve this transformation is the view entertained by some distinguished pathologists.^ The mus- cular substance, according to this view, undergoes a metamorphosis, the same elements recombining to form the fatty matter, as muscu- lar tissue after death is supposed to be converted into adipocere. If this view be correct, it is not strictly accurate to call the fatty matter a deposit ; it is not, at all events, deposited primarily as fat, but as the substance of the muscle. Nor is the change due to perverted nutrition ; it is due to a chemical, not a vital process. A more philosophical explanation attributes the change to a process of replacement rather than conversion. The fat is strictly an abnormal deposit, which takes the place of the muscular substance. The change, agreeably to this explanation, does not consist, pro- perly speaking, in a degeneration of structure, but in the substitu- tion of one anatomical element for another, and it has been proposed to employ, as a more accurate mode of expression, the term suhsti-
' Rokitansky and Jones & Sieveking may be consulted for this object.
^ For the evidence to be adduced in support of this doctrine, the reader is referred to an article by Dr. Richard Quain (in Medico- Chirurgical Transactions, vol. sxxiii.) on Fatty Disease of the Heart.
FATTY GROWTH AND DEGENERATION". 93
tution instead of degeneration.' Thej who adopt the latter view regard atrophy of the muscular tissue as the first step in the local pathological process. The anatomical elements within the sarco- lemma disappear by absorption, and fat is deposited in their place. It is, perhaps, as reasonable to suppose that the primary change is the fatty deposit, the removal of