SYMPOSIUM ON CORONARY HEART DISEASE Auscultatory Findings in Myocardial Infarction

rick ' wrote in 1912 "The heart tones have been feeble-in fact, often startlingly feeble. Feeble contraction of the weakened, anemic heart musele accounts for the weak pulse and the weak tones. " A review of currenlt texts on heart disease2-4 gives much the same in-formation. Iittle investigative work has beeii done on this subject, which is not partieularly surprising when one realizes that electrocar-diography and not auscultation is the more precise method of diagnosis in acute myocar-dial infaretion. Other reasons for the lack of precise knowl-edge are the technical difficulties of making phonocardiogranms or tape recordings and in doing hemodynamic studies during the acute phase of myocardial infaretion. These diffi-culties inelude the critical condition of the patient, environmental noise, and the lack of any standardization technic for phonocardi-ography that allows accurate comparison of initensity and frequeney of the heart sounds from patient to patient. Bean5 noted that the heart sounds were described as weak, distant, or muffled in about 80 per cent of 160 cases of acute myoeardial infaretion and the loudness of the sounds was inversely related to the degree of shock in most cases. A phonographic study of heart sounds in acute myocardial infarction was done by Parsonnet and Hyman6 in 1931, but because of lack of accurate recording equip-ment at that time it is difficult to evaluate their results in light of present technics. In 1942 Masters and Friedman,7 using bette