Total Cardiac Vibrations in Aged Hearts and in Coronary Disease

Abstract

By means of the vibrocardiograph 1 it is possible to record all the cardiac vibrations (audible and inaudible) that are transmitted through the chest wall. A study of the vibrocardiograms of 100 normal young adults, 2 taken from the usual auscultation areas, established the presence of dominant vibration groups at the onset of systole and at the second sound. These curves were dissimilar to the usual stethogram, as the vibration groups were modified by low-frequency (inaudible) components with which the sound elements are mixed. In 5% of the tracings there appeared low-frequency waves (approximately 1-5 dv. per sec.), the largest mound occurring in mid-systole and two or more in diastole. These waves were of very low amplitude.

The vibrocardiographic curves of 102 individuals over 55 years of age, with and without evidence of coronary disease, were examined. The cases fell into three groups: those with clinical and electrocardiographic evidence of coronary disease (34 cases); those with objective evidence but with normal electrocardiograms (33 cases); and those with no evidence of heart disease. Cases having definite evidence of coronary disease, despite the presence or absence of electrocardiographic change, all showed a prolongation of the total vibration complex at the onset of systole. Normally this complex averages 0.22 second in duration; in these cases the average length was 0.33 second. In some instances of severe myocardial damage, deflections of low frequency with occasional steep slopes occupied nearly all of systole, and on auscultation the sounds were “impure” and muffled. In most of these tracings large, low-frequency waves appeared in systole and diastole similar to those seen in some normals, except that they were definitely augmented in amplitude, occasionally becoming as tall as the most dominant sound deflections; they were in phase with each other and with the onset of ventricular systole.