Reappraisal of some problems concerning the genesis of heart sounds.

This paper sums up for clinical purposes the recent data and some of the authors' own observations concerning the genesis and variability of heart sounds. The importance of some factors in the "cardio-hemo-vasculo-thoracic" complex where the heart sounds are produced and transmitted, is especially emphasized; such are: acceleration and decelaration of the blood, rapidly variable shape and compliance of the cardiovascular container, turbulence phenomena, atrial and ventricular contraction and relaxation, closure and opening of cardiac valves. The role of some physiological or pathological changes in myocardial contractility and compliance in over- or underdamping of intracardiac vibrations generating heart sounds, is also analysed. Some examples of alteration of the 4th, 1st, 2nd and 3rd sound in the 3rd degree A--V block, nodal rhythm, short P--R, LBBB, aortic atherosclerosis, myocardial infarction, are presented.