Systolic murmurs in 525 healthy young adults.

Much has been written by physicians about patients referred to them because of the discovery of a systolic murmur. Inevitably such consultant physicians have scant opportunity to judge the incidence, character, and significance of murmurs among apparently healthy people. Freeman and Levine (1933) described the systolic murmurs that they had found in a group they had examined of a thousand persons whose cardiovascular systems had been supposed normal: the value of their investigation would appear lessened by the fact that most were hospital patients suffering from illness in some other form. Contratto (1943) published an account of the systolic murmurs that he had elicited among a group of healthy Harvard students without, however, making any attempt to analyse the variability induced by altering the conditions of examination. A similar study carried out by O'Meara (1947) upon recruits to the Royal Navy made no mention of the important factor of loudness. In the paper that follows the object will be to consider, in somewhat greater detail than is commonly possible at routine clinical examinations, the systolic murmurs heard in a large group of healthy young adults. All murmurs must be the product alike of cardiac structure and function. They may derive from local or general disease, or as a variant of the normal. The conception of this innocent or, in Parkinson's phrase, " incidental" systolic murmur has been twice revolutionized within the last generation. In consequence, largely, of the work of Mackenzie (1925), there developed the idea that an apical systolic murmur, no matter how loud, was of no importance so long as cardiac function remained good and other signs were absent. Reaction against this belief, already begun by Levine and others, was accentuated by observations made during the 1939-45 war. Parkinson and Hartley (1946) emphasized the new orientation: in 60 out of 2500 of the recruits referred to them by medical boards-they diagnosed mitral stenosis on the strength of a systolic murmur alone. Referring to the same problem Master (1948) wrote : "It should be evident that proper evaluation of a loud apical systolic murmur in the absence of enlargement of the heart, diastolic murmurs, abnormal electrocardiograms, and heart failure, is of paramount importance in medical practice ... I believe that this murmur should be accepted as evidence of organic heart disease unless cardiac abnormality can be disproven." But how loud? And how can cardiac abnormality ever be disproven? To use such a phrase is surely to beg the question. Rather must all diagnosis rest upon the reciprocal assumptionthat the absence of recognizable defect proclaims the normal. There has thus to be formed a critical assessment as to whether any particular murmur should be designated innocent or organic. The points examined to that end in the present series are those advocated by most authorities. It is hoped that the findings may prove of value as a control, affording a background for the clinical appraisal of patients suspected of cardiac disease on account of a systolic murmur.