CHAPTER 22 



Phonocardiography 



D A \' I D H . LEWI S' 



Philadelphia General Hospital and Graduate School of Medicine 

 University of Pennsylvania, Philadelphia, Pennsylvania 



CHAPTER C:ONTENTS 



Physical Basis for the Production of Heart Sounds 

 Physical Basis for the Production of Murmurs 

 Physical Basis for the Transmission of Sounds and Murmurs 

 Physiological Basis of Acoustics 



Relationship of Heart Sounds to Events of the Cardiac Cycle 

 First heart sound 

 Second heart sound 

 Third heart sound 

 Fourth heart sound 

 Relationship Between Acoustic Events and Other Physio- 

 logical Parameters 

 Electrocardiogram 

 Jugular venous pulse 

 Carotid artery pulse 



Low frequency recordings from the thorax 

 Effect of Respiration on Heart Sounds 



Effect of Alterations in Electrical Activity on Heart Sounds 

 Heart block 

 Bundle branch block 

 Effect of Disease States on Heart Sounds 

 Abnormal Heart Sounds 

 Gallop sound 

 Diastolic knock 



Opening snap of atrioventricular valve 

 Systolic clicks, systolic gallops, and ejection sounds 

 Pericardial friction rub 

 Murmurs 



Murinurs of valvular origin 

 Murmurs of nonvahular origin 

 Effect of Respiration on Murmurs 

 Effect of Pharmacological Agents on Murmurs 

 Method of Identification of Site of Origin of a Murmur 

 Intracardiac Phonocardiography 

 Current Problems in Cardiovascular Acoustics 



' Established investigator, American Heart Association. 

 Supported by a grant-in-aid froiB the American Heart Asso- 

 ciation, by a research grant (H-2559) from the National 

 Institutes of Health, and by a contract (Nonr 2744-00) from 

 the Office of Naval Research, Department of the Navy. 



HISTORICALLY, cardiac acoustics may be said to begin 

 with Harvey (40), and phonocardiography, the 

 graphic representation of cardiac acoustics, with 

 Einthoven (29). Both of these complementary types of 

 information have traditionally been more tlie prov- 

 ince of the clinician than of the pliysiologist. Although 

 no one would suggest that tlie pendulum has swung 

 the other way, there appears definitely to be a rise in 

 interest in the physiological aspects of cardiac acous- 

 tics and phonocardiography. This shift in emphasis 

 seems to stem from a change in the bases of our 

 knowledge. Until recently, questions raised by cardiac 

 acoustics at the bedside could be answered only by 

 the gross anatomy seen at the autopsy table. With the 

 advent of cardiac catheterization and its related tech- 

 niques, interest has begun to move away from purely 

 anatomical concepts to tiiinking in functional terms. 

 The growth of this new body of knowledge, mainly in 

 the field of human cardiovascular physiology, has 

 been rapid and, as of this date, incomplete. The pur- 

 pose of this communication is to survey what is cur- 

 rently known concerning the physical and physio- 

 logical bases of heart .sounds and murmurs, and to 

 indicate what gaps exist in this information. Since the 

 author's experience has been almost wholly in the 

 field of human cardiac acoustics, the material to be 

 presented will be drawn from this species. However, 

 no attempt will be made here to catalogue the sounds 

 and murmurs in the various types of human cardiac 

 lesions. For those interested, reference should be made 

 to one of the several recent monographs in the field 

 (17, 41, 57, 68, 76, 81) or the two recent symposia 

 (69, 70). Those lesions that seem pertinent will be 

 discussed as they serve to illustrate physiological 

 principles. 



Since the following presentation divides itself 



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