Complete Text (Part 9)

of maximum intensity being usually at the junction of the fourth rib with the sternum ; and they do not often last long, disappearing frequently after a few hours, or at most in a few days. A pericardial murmur is distinguished from an endocardial by its rubbing quahty, by its superficial character, and by its Tbot being transmitted beyond the limits of the heart, either along the arteries or round the left side to the back. It may also be distinguished from a valvular murmur by its intensity varying with a change in the position of the patient, and by its inde- pendence of the heart sounds. Endocardial or Valvular Murmurs, In endocardial murmurs, the elements of quality and inten- sity hold but a subordinate place as regards either diagnosis or prognosis. The same murmur may be at different times, MURMURS. 97 blowing, grating, rubbing, or musical, In cbaracter, without its significance altering in tlie least through all these changes in its quality. " The mere fact that a murmur exists, and has a certain acoustic quality, tells very little as regard? the true character of a case."* Practically speaking, endo- cardial murmurs may be regarded as "audible announce- ments " that something has occurred to roughen the surfaces of the endocardium, or to constrict the orifices of the heart, or to render the valves insufficient, so that they allow the blood to regurgitate, or to diminish the elasticity of the great vessels, or finally, that some change has taken place in the natural constituents of the blood itseK. Having ascertained the existence of a cardiac murmur, the first question then is, What is its pathological significance, or in what way has it been produced ? To determine this, it is necessary to observe particularly two points : 1st, The rhythm ; and, 2d, The seat of the murmur. The Rhythm ©f a Murmur. — Under this head we ascertain the relation of a murmur to the difi'erent physiological acts which constitute a complete cardiac pulsation. We define the murmur as occurring during either portion of the heart's action, or during the rest which intervenes between the periods of activity. To do this, we note carefully its relation to the normal sounds, to the impulse, and to all the other appreciable phenomena which attend upon the heart's action. By referring to fig. 13, you have before you the whole audible and tangible phenomena of the heart's action, and their rela- tion to the physiological movements which cause them. Evidently the first step is to determine which is the first, and which is the second sound of the heart. When the * In treating of tlie significance of the cardiac mumiur, I have followed Dr. Gairdner's method in preference to any other with which I am acquainted, and. in some instances have adopted his phraseology. 98 PHYSICAL DIAGNOSIS. heart's action is slow and regular, this is quite an easy matter ; but when the heart is acting rapidly, it is always difficult, and sometimes impossible, to distinguish the one sound from the other. It is important, therefore, not only to know theoreti- cally all the visible phenomena of the physiological action of the heart, but it should be a famihar tangible knowledge. Having identified the two sounds, and traced their relation Fig. 15. Diagram illustrating the 3fode rf Production of Cardiac Murmurs in the Left Heart, and the Condition of the Valves and Cavities during their Production. By substituting the words Tricuspid and Pulmonary, for Mitral and Aortic, the Diagram will similarly illustrate Mur- murs Occurring in the Right Heart. to the apex beat, and the radial pulse, the rhythm of a mur- mur is readily determined ; for all valvular murmurs either precede, or take the place of, or immediately follow one of the heart sounds. First. A murmur may precede and run up to the first sound, ending at the moment of the sound, and with the apex beat. In this case, as shown by fig. 15, the murmur is simultaneous with the contraction of the auricles, and is called a mitral or tricuspid ohstructive murmur, as it is produced on the right or left side of the heart, while the blood is passing from the MUEMUES. 99 auricles to the yentricles. Sucli murmurs, therefore, depend either upon contraction of the mitral or tricuspid orifices, or upon deposits on the auricular surface of these yalves, causing obstruction to the flow of blood out of the auricle during its contraction. Second. A murmur may take the place of, or follow the first sound, ending somewhere between the first and second sounds. In this case the murmur is coincident with the contraction and emptying of the ventricles, and must be caused, as is shown in fig. 15, either by obstruction to the current of blood as it flows outwards from the ventricles, in its natural direc- tion into the aorta and pulmonary artery ; or backwards by regurgitation, through the mitral or tricuspid valves. If it occur on the left side of the heart, it is called either aortic obstructive, or mitral regurgitant murmur ; if it occur on the right side of the heart, it is called either pulmonic obstructive, or tricuspid regurgitant murmur. Third. A murmur may take the place of, or follow the secoTid sound, ending somewhere during the interval between the second and first sounds ; in some instances it may be pro- longed through the whole period of rest. This murmur is simultaneous with the dilatation of the ventricles (fig. 15), and is produced by regurgitation of blood through the aortic or pulmonary valves, and is called either aortic regurgitant or pulmonic regurgitant murmur. We may have, therefore, eight distinct endocardial murmurs, four systolic, and four diastolic. Not unfrequently we find in practice, various combinations of these different murmurs in the same case. For instance, it is not unusual to have a mitral obstructive and mitral regurgitant murmur combined, so as to appear to constitute one murmur ; the first sound of the heart will, however, enable you to separate the two mur- murs. In Hke manner, an aortic obstructive and regurgitant murmur are frequently combined ; here also the sound inter- 100 PHYSICAL DIAGNOSIS. venes, and makes the rhytlim quite plain. The greatest diffi- culty is when the normal sound is merged into the murmur, as is often the case when the mitral obstructive and regurgitant are combined. The precise pathological significance of endocardial murmurs is apparent from the following table : TABLE OF CARDIAC MUEMTmS.* Periods of Heart's Action. Seat of Murmur. Systolic. Left side of heart. Aortic Mitral Cause ofMwrmur. f Obstruction to the onward flow of blood through the aortic orifice, or througli the aorta. Regurgitation of blood through the mi- (^ tral valve into the left auricle. Pulmonary Eight side _ of heart Tricuspid ' Obstruction to the onward flow of blood through pulmonary orifice, or through pulmonary artery. Regurgitation of blood through the tri- cuspid orifice into right auricle. Diastolic. C Aortic Left side J of heart, i [Mitral Right side of heart. 'Pulmonary Tricuspid . Regurgitation of blood through the aortic orifice into left ventricle. Obstruction to the flow of blood from left auricle to left ventricle. Regurgitation of blood through the pulmonary orifice into right ven- tricle. Obstruction to flow of blood from right auricle into right ventricle. Although eight distinct valvular murmurs may occur in the heart ; those on the right side are of such rare occurrence, that they are of little clinical importance. If a murmur is heard with the first sound of the heart, it is almost certainly aortic ohstrudive, or mitral regurgitant; if with the second sound, it is probably aortic regurgitant. An obstructive mitral murmur is also of comparatively rare ♦After Fuller. MITRAL MURMURS. JQl occurrence ; the force with which the blood passes from the auricle into the ventricle being ordinarily insufficient to excite sonorous vibrations. Seat of Murmurs. — Having determined the rhythm of a murmur, the next step in the investigation is to find within as narrow limits as possible the place of its origin. The points at which endocardial murmurs are produced, being in the majority of cases one of the four valvular orifices, the first question to be settled under this head is, at which one of these valvular orifices it is produced ? At the commencement of the examination, every means shoidd be taken to determine in each particular case the actual size and position of the heart, together with its relation to the thoracic walls and to the surrounding organs, the exact point of the apex beat, and the character of the im- pulse. We must endeavor by careful stethoscopic examiuation to determine the exact seat, and the limits of diffusion of the murmur under observation. If the murmur is very loud or diffused, or if there are several murmurs present in the same case, it may give rise to some difficulty ; but in the large majority of cases the observer will be able to fix on a few points, or a few restricted spaces, over which each murmur is heard, there being no murmur elsewhere ; or, if not so, areas within which each murmur is heard with greatest intensity. As there are four valvular orifices at which the majority of endocardial murmurs are produced, so there are four distinct areas to which murmurs arisiug at these orifices may be prop- agated. The following rules will be found useful in recognizing these areas in actual practice : I. — Area of Mitral Murmurs. — The maximum of intensity of mitral murmurs corresponds generally with the apex of the 102 PHYSICAL DIAGNOSIS. left ventricle, represented in fig. 16 by the circle A. If it is produced by regurgitation of blood through mitral orifice, its area of diffusion is to the left, on a line corresponding to the apex beat ; the seat of diffusion in front corresponds very nearly to the circle A, fig. 16 ; and it is also heard with very Fig. 16. Diagram showing the Areas of Cardiac Murmurs. These several Areas correspond to tht Different Spaces marked by the Dotted Lines, and a Capital Letter Designates each Area. A, the Area 0/ Mitral Murmurs ; B, of Aortic; C, of Tricuspid ; and D, of Pulmonic— . Gajbdnbb. nearly the same intensity behind, between the lower border of the fifth, and upper border of the eighth vertebra, at the left of the spines as in front. The area of diffusion of mitral obstructive murmurs is TRICUSPID MURMURS. 2Q3 usually limited to a circumscribed space (circle A) around the apex of the heart; in some instances these murnftirs are heard with equal intensity over the whole superficial cardiac region. To the left of the apex beat they are always indis- tinct, and are never heard heliind. 11.— Area of Tricuspid Murmurs.— The area of tricuspid murmurs corresponds to that portion of the right ventricle which is uncovered by lung tissue, indicated in the diagram by the triangular space C. This murmur is distinct and superficial in character, rarely audible above the third rib, and thus readily distinguished from the aortic and pulmonic mur- murs. It is heard loudest near the xiphoid cartilage, and along the margins of the sixth and seventh costal cartilages. In cases of hypertrophy and dilatation of the right side of the heart, usually its point of maximum intensity is at the junction of the fourth rib with the sternum. Area of Pulmonic Murmurs. — Murmurs in the pulmonary artery, or at the pulmonary valves, are carried to the ear nearly over the seat of the valves, as indicated by the circle D in the diagram, fig. 16. Not unfrequently its maximum point of intensity is an inch, or even an inch and a half, lower down. It is usually very superficial, and consequently very distinct. It is limited in its diffusion, being inaudible at the apex, and also along the sternum ; it is never heard in the neck, nor in the course of the great vessels. Area of Aortic Murmurs. — Tlie law of diffusion of aortic murmurs is not easily explained ; not only are they heard with great intensity over the base of the heart, at the junction of the third rib with the sternum on the left side, but fre- quently, and not less distinctly, along the whole length of the sternum, as is indicated by the dotted lines along the edge of the sternum, in the in-egular space B, fig. 16. Sometimes they are absolutely louder close to the xiphoid cartilage than at any other point. An aortic murmur is distinguished from 104 PHYSICAL DIAGNOSIS. all other murmurs by being propagated into the arteries of the neck. It is the most widely diffused of all cardiac mur- murs, and can sometimes be traced to a very great distance from the heart, and may be heard behind near the lower angle of the scapula. To complete the diagnosis of endocardial murmurs it is necessary to consider their rhythm in connection with their area. First. A murmur which immediately precedes the first sound of the heart, may be either a mitral or tricuspid obstructive murmur, and is produced by obstruction to the current of blood as it passes from the auricles into the ventricles. If it is a mitral obstructive murmur, its maximum of intensity will correspond to the circle A, fig. 16 ; if, on the contrary, it is a tricuspid obstructive murmur, its maximum of intensity wiU be within the triangle C. Second. Murmurs accompanying or following the first sound, and occurring between the first and second sound, may be pro- duced, either in the auriculo-ventricular, or in the arterial orifices, and they have four distinct solutions. a. If a murmur following the first sound has its origin at the mitral orifice, it is a mitral regurgitant murmur, and is pro- duced by regurgitation of the blood backwards from the left ventricle into the left auricle. Its maximum of intensity in front will correspond to the circle A, fig. 16 ; and it will be heard behind. h. If its origin is at the tricuspid orifice, it is a tricuspid re- gurgitant murmur, and is produced by regurgitation of the blood backwards from the right ventricle into the right auricle. Its maximum of intensity will correspond to the tri- angle C,fig. 16. c. If its origin is at the aortic orifice, it is an aortic obstruc- tive murmur, and is produced by obstruction to the current of blood as it passes in its natural course^ from the left ventricle ANEMIC AND FUNCTIONAL MURMURS. 105 into the aorta. Its maximum of intensity will correspond to the irregular space B, fig. 16. d. If its origin is at the pulmonic orifice, it is a pulmonic obstructive murmur, and is j)roduced by obstruction to the cur- rent of blood as it passes from the right ventricle into the pulmonary artery. Its maximum of intensity will correspond to the circle D, fig. 16. Again, murmurs accompanying or following the second sound of the heart may be produced at the aortic or pulmonic orifice, and in either case coincide with the filling of the ven- tricles. a. If a murmur accompanying or following the second sound has its origin at the aortic orifice, it is an aortic regurgi- tant murmur, and is produced by the regurgitation of the blood from the aorta backwards into the left ventricle. Its maximum of intensity corresponds to the space B, fig. 16. h. If a murmur following the second sound has its origin at the pulmonic orifice, it is a pulmonic regurgitant murmur, and is produced by the regurgitation of blood fi'om the pidmonary artery into the right ventricle. Its maximum of intensity corresponds to the space D, fig. 16. One, two, three, and even four of the murmurs we have been considering, may occur in combination in the same case. The most frequent combinations are the aortic obstructive and regurgitant heard over the area B, fig. 16 ; next, the mitral obstructive and regurgitant heard over the area A ; then we have various combinations of these, the aortic and mitral valves being both diseased. Murmui's occurring on the right side of the heart are com- paratively of rare occurrence ; the tricuspid regurgitant being the only one that is of practical importance. Anaemic and Functional Murmurs are soft and blowing in character, are always systolic, and almost always aortic. As regards their area, they are generally diffused, not only over 106 PHYSICAL DIAGNOSIS. the base of the heart, but along the course of the aorta and the vessels of the neck. An anaemic is distinguished from an organic murmur by its blowing character ; by always accompanying the first sound of the heart ; by being audible in several of the arteries at the same time ; by not being constantly present, occasionally disappearing when the circulation is tranquil, and returning when it is accelerated ; by the presence of the general signs of anaemia ; by the absence of the physical or general signs of organic disease of the heart ; by entirely disappearing under treatment calculated to relieve the anaemic state of the system. Venous Murmurs all come under the class of inorganic murmurs. The so-called venous hum is a continuous hum- ming sound, having frequently a musical intonation. It is best heard over the jugular just above the clavicles, the patient being in a sitting or standing position. It is charac- teristic of anaemia, and is almost always associated with an arterial anaemic murmur. Before leaving the subject of cardiac murmurs, I wiU give you some rules in relation to them, copied from the unpub- lished writings of the late Dr. Cammann ; they are the result of long and careful observation, and although they differ in some respects from the teachings of many auscultators, I