Complete Text (Part 8)

sec- ond. Hence it is that, when the heart is acting rapidly, it is difficult to distin- guish the first sound from the second, and vice versa; while with the slowly acting heart this difficulty does not occur. Attention to these varieties — physiological varieties they may be called — ^in the rhythm of the soimds is of very great importance in determining the attributes of a cardiac murmur ; for the first step in the inquiry is to deter- mine which is the second sound and which is the first ; and this, as I have said, is sometimes not quite an easy matter. Generally speaking, and in all cases when the action is slow and regu- lar, there is no difficulty ; you have only to remember that the longer interval is between the second and first sounds, and the shorter interval between the first and second; but when the action is rapid or irregular, and when the first sound is indis- tinct at the apex, or cannot be identified with the apex beat, and also when the second sound is indistinct, or when it is audible only at the base, the first sound being audible only at the apex, as sometimes happens, the difficulty of recognition of the two sounds is very considerable. LESSON X. Methods of Cardiac 'Pfij'sical JSJxamination. The metliods of physical examination of the heart include inspection, palpation, mensuration, percussion, and auscultaticm. By Inspection you note the exact point of the heart's im- pulse where it strikes the walls of the chest, and also whether there is any unusual pulsation, or any change in the form of the cardiac region. In a perfectly normal chest, the infra- mammary regions on either side are very nearly symmetrical ; but in disease, the prsecordial region may either be depressed, or on the contrary arched forward, and the intercostal spaces be widened. The most important information furnished by inspection relates to the cardiac impulse. This, in the major- ity of persons, is visible only in the fifth interspace, midway between the left nipple and the sternum, and its area does not exceed a square inch. You will generally find it most distinct in thin persons, while in fleshy individuals it is sometimes scarcely discernible ; and you will also find that it may be modified by position, by distension of the subjacent stomach, and by the movements of respiration. Thus during a full in- spiration you may note the impulse down in the epigastrium, and then during a forced expiration see it elevated and more diffused. In disease you may find the impulse altered as respects its position, its area, or its force. Thus it is tilted upwards and outwards by enlargement of the left lobe of the liver ; or it may be crowded over to the right side and downwards by simple pleuritic effusion or emphysema, so that I have seen it 88 PHYSICAL DIAGNOSIS. beating even externally to the right nipple ; it may also be forced upwards by pericardial effusion, or downwards and to the left in cardiac hypertrophy. Not unfrequently in cases of pericardial agglutination, or dilatation of the ventricles, an undulating impulse will be visible. Palpation. — This is of much greater clinical importance than inspection. By it we determine the force of the cardiac pulsation; the frequency or slowness of the heart's action; and the regularity or irregularity of its movements. By it also we detect the presence of the friction fremitus, and what is termed the "purring tremor^ The force of the cardiac impulse may be diminished or in- creased. Diminution of the Impulse may depend either upon feebleness of the action of the heart in consequence of de- generation of its tissues, and in cases of prostration of the whole system as in collapse ; or upon the apex of the organ being prevented from impinging against the walls of the chest with its customary force, as happens in disease of the lungs and pericardium. Increase of the Impulse. — In the majority of instances this is caused by hypertrophy of the walls of the left ventricle, and a slow progressive impulse can be produced by no other cause. In such cases the area over which the cardiac impulse can be felt is much increased. In the early stage of endocar- ditis, and of pericarditis, and in palpitations from functional disorders, the impulse is slightly increased. Change in the Situation of the Impulse. — A change in the situation of the cardiac impulse may occur as the result either of hypertrophy, or of displacement of the heart from disease of the lungs or pleura. The frequency and regularity of the heart's action is of great importance in the diagnosis of cardiac disease ; and it can often be most accurately determined by palpation. PERCUSSION. 89 The Purring Thrill (the ''fremissement cataire " of Laennec) is a peculiar vibratory sensation perceptible on making pres- sure at the prsecordium. In some the pressure need be but shght, while in others it should be firm. It may also be com- municated by the large arteries, etc. Percussion. — By percussion we aim to make out the exact outline of the heart itself, and of its investing membrane, to determine whether it exceeds its normal area ; and to do this well, you will find both care and practice requisite. In per- forming cardiac percussion, the patient should be in a recum- bent posture, and you need tap but lightly over the part where the heart is not covered by lung tissue, to obtain a flat sound. Where, however, the lungs overlap the organ, you must percuss more forcibly to eHcit cardiac dulness, and this soimd wiQ of necessity have more or less of a pulmonary qual- ity. We have, therefore, two degrees of cardiac dulness, — the superficial and the deep-seated. In health the area of the superficial dulness does not exceed two inches in any direction ; it is triangular in form, with the apex immediately below the junction of the left third rib with the sternum, whUe the base is on a hne with the cartilage of the sixth rib. The area of the deep-seated dulness ia health extends transversely from the left nipple to half an inch to the right of the sternum, and vertically from the second to the sixth interspace. The area of the heart's superficial dulness may be increased or diminished ; increased, when the ventricles are hypertro- phied, or when their cavities are dilated, and also when the pericardium contains fluid ; diminished, at the end of a full inspiration, and in pulmonary emphysema from its inducing a general distension of the air cells. The area of the deep- seated dulness is increased by enlargement of the heart, whether this be due to ventricular dilatation, or to hyper- trophy of its muscular parietes ; and it is apparently increased by consohdation of the anterior border of the investing lung, 90 PHYSICAL DIAGNOSIS. and also by fluid in the left pleural cavity. We are also often mucli assisted in determining the limits of the deep-seated dulness in certain cases by auscultatory percussion. Auscultation. — For reasons already stated I prefer mediate to immediate auscultation in examining the heart, and in practising it you will find of service the following simple rules : 1. The posture of the patient should be recumbent when you begin your examination. Then, having carefully elicited aU the auscultatory symptoms which this posture affords, re- peat your examination with him sitting or standing, and note whether any variations in the sounds heard have occurred from the change in his position. 2. You should first listen to the heart sounds while the patient is breathing naturally; having done so, then direct him to hold his breath for a moment ; and finally tell him to take three or four forced inspirations. These various means are often aU required before we can correctly discriminate between the different signs in cardiac auscultation. 3. You should not confine your examination to the prsecor- dial region alone, but should explore the whole thoracic cavity and endeavor to locahze the points at which the heart sounds, both normal and abnormal, are heard with the greatest inten- sity. To this end proceed in your examination from below upwards, and from left to right. As in the case of pulmonary auscultation, so here, the nor- mal characters must be the starting-point or standard by which every system in cardiac auscultation is to be compared. You cannot, therefore, pay too much attention towards ac- quiring a familiarity with the elements of the heart sounds in health. These elements are as follows : When the ear or stethoscope is appHed to the praecordial region, two successive sounds are heard, followed by an interval of silence, which therefore does not intervene between the first and second, but between the second and first. The first sound is softer, lower MECHANISM OF HEART SOUNDS. 91 in pitch, and more prolonged than the second ; as has already been shown in fig, 13, it coincides with the systole of the ven- tricles and with the apex beat ; it immediately precedes the radial pulse, and has its maximum of intensity in the fifth in- terspace, a httle to the right of the left nipple. The second sound is sharper, or higher pitched, shorter and more superfi- cial than the first. It is synchronous with the diastole of the ventricles, occurs after the pulsation of the arteries, and has its maximum of intensity at the jimction of the third left rib with the sternum. The period of silence immediately following the second sound varies in length with the rapidity of the heart's action. The order and duration of the respective periods of the soimds, and the silence, you will be able to appreciate best by refer- ring to diagram Nos. 13 and 14. The intensity of the heart sounds varies m health according to the force of the heart's action, or according to the confor- mation of the chest, or according to individual idiosyncrasies. These sounds are less intense in fleshy or muscular persons with capacious chests, than in thin, narrow-chested, and nerv- ous individuals. The extent of surface over which the heart sounds are heard varies mth the adaptation of the adjacent organs for transmit- ting sounds. Generally speaking, the sounds produced on the right side of the heart are more audible on the right side of the prsecordial region ; while those produced on the left are more pronounced on their corresponding side. Mechanism of the Heart Sounds. — There has been much dijBference of opinion on this subject. My own opinion is this : that the first sound is produced by the closiu'e of the mitral and tricuspid valves ; also that it has in addition elements in its production which are not valvular; namely, sound from the impulse of the heart's apex against the thoracic walls, from the contraction of the ventricles, and, lastly, fi-om the 92 PHYSICAL DIAGNOSIS. friction of the blood against tlie walls of the ventricles, and against the ventricular surface of the valves. Some eminent authorities, however, regard the closure of the above-mentioned valves as the one and only cause of this sound. As to the second sound, all are agreed to its proceeding from the sudden closure and tension of the aortic and pulmonary valves, by the reflux of the blood on them during the diastole of the heart. Pathological Modifications of the Normal Sounds. — In disease, the normal sounds of the heart present various definite alterations as regards their intensity, quahty, pitch, seat, and rhythm ; and they may also be accompanied, pre- ceded, or followed by adventitious sounds or murmurs. An iruirease of intensity may be noted in cases of hyper- trophy and dilatation of the ventricles ; in cases also of nervous irritability of the heart, or where there is consoKda- tion of the adjacent lung tissue. A diminution in intensity may be found depending either upon dilatation of the ventri- cles without hypertrophy of their walls ; or upon fatty degen- eration of the muscular tissue of the heart ; or on softening of the same, as ia typhus and typhoid fevers ; or it may be owing to a mufaing of the heart sounds by pericardial effusion, or by emphysematous 'distension of the anterior border of the lung. Alterations in Quality and Pitch.— The heart sounds in disease may become dull and low-pitched, or sharp and high- pitched. The first sound is dull, muffled, and low-pitched, when hypertrophy is conioined with a thickened condition of the aiu'iculo-ventricular valves. On the other hand, where the ventricular walls are thin, and the valves natural, the first sound becomes sharp and clicking in character, and the pitch is raised. The second sound is rendered dull and low-pitched, by diminished elasticity of the arterial walls, and by thicken- ing of the aortic valves, without regurgitation. Sometimes-the MODIFICATIONS OF NORMAL SOUNDS. 93 heart sounds liave a metallic or tinkling quality which depends either upon an irritable action of the heart, or on a gaseous distension of the stomach. Alterations in Seat.— This refers to the points of the maximum intensity of the respective sounds, which may be displaced, 1st, upwards by certain changes in the abdominal viscera ; or, 2d, downwards, by tumors in the mediastinum, and by hypertrophy with dilatation of the auricles ; and lastly laterally, by the accimaulation of au- or fluid in the pleural cavities. Malformations of the thorax may likewise displace them in different directions. Alterations in Rhythm. — It not unfrequently happens that a distinct intermission occurs in the heart's action. After a certain number of regular beats, a sudden pause or silence occurs; the heart's action seems to be suspended for an instant, and then to go on regularly. This intermission is often observed in individuals who are in perfect health. It also occurs in diseased states of the valves or orifices of the heart. It is difficult to explain its cause, and it has no pre- cise pathological significance. Irregularity in the Heart Sounds, however, constitutes another and different alteration iu rhythm. The sounds be- come confused and tumultuous ; they are alternately loud and feeble ; at one time slow for two or three beats, and then they follow each other in rapid succession. When the irregularity is permanent, it is almost 'positive evidence of organic disease of the heart ; the most frequent form being contraction of the mitral valves. One or both of the heart sounds, as well as the period of rest, may be j)rolonged or shortened. In hypertrophy of the ventricular walls the first sound is prolonged. In dilatation of the cavities of the ventricles it is shortened. The first sound is also prolonged when the two surfaces of the pericar- dium are adherent. An obstacle to the flow of the blood into 94 PHYSICAL DIAGNOSIS. the ventricles prolongs the period of repose. Another altera- tion in the rhythm of the heart sounds is named reduplication. Each systolic sound may be repeated twice for one diastolic ; or the diastolic may occur twice for one systolic. Sometimes only one sound is audible. The essential cause of the various reduplications seems to be a want of synchronism between the action of the two sides of the heart, but they are of slight clinical importance. LESSON XI. iibnormal Sounds of the Heart. Pericardial and Endocardial Murmurs, The term murmurs has been applied to those adventitious sounds which accompany or replace the normal sounds of the heart, and which are not heard in health. Their seat may be either within the heart , at the orifices of the ventricles, when they are called endocardial or valvular murmurs ; or they may be external and in the pericardium, when they are termed exo- cardial or pericardial friction sounds. Pericardial Friction Sounds. — The pericardium is a serous membrane investing the heart, as the pleura invests the ad- jacent lung ; and therefore when it is inflamed we have exactly analogous results with those which we described as appertain- ing to pleurisy ; namely, first dryness, and then plastic and serous effusion, with the different friction sounds which are caused by the rubbing of the roughened surfaces of the opposed membrane upon one another during the movements of the heart. This similarity sometimes makes it a nice point in diagnosis to distinguish a pericarditis from a pleuritis, but the determining consideration will be, that when it appertains to the heart, it is limited to the prsecordial space, or at least that it is synchronous with the cardiac, and not with the respi- ratory movements. The different forms of the pericardial friction sounds have been named, like those in pleuritis, grazing, rubbing, creaking, rasping, etc. Clinical experience, however, does not always 96 PHYSICAL DIAGNOSIS. show any definite connection between the state of the serous surface and the quality of a friction sound. The grazing variety appertains to the initial stage of the inflammation ; the other varieties occur after the plastic effusion, and while it is undergoing organization. These sounds vary in intensity, from the slight rusthng which can be heard only by close at- tention, to a loud rasping sound audible before your ear is appHed to the chest. As a rule, they become more distinct during expiration than inspiration, and while the patient is sitting, rather than while recumbent, owing to the greater ap- proximation of the pericardium to the chest wall during these states. Pericardial friction sounds may be single or double, that is, accompanying both the systolic and the diastolic movements, or either one singly. They may accompany the valvular sounds, or be independent of them ; and they always convey the im- pression of being superficial in comparison with the endocar- dial murmurs. They are generally restricted to the pericar- dial space, the point