Origin of Heart Sounds as Elucidated by Analysis of the Sequence of Cardiodynamic Events

Abstract

Evidence for the valvular origin of the first heart sound was obtained by simultaneous phonocardiograms and pressure pulses from the left atrium and left ventricle in patients with mitral stenosis. It was consistently observed that the first heart sound begins at the time of mitral valve closure, significantly after the onset of left ventricular contraction. Hemodynamic observations which explain the splitting of heart sounds in the normal and in diseased states were briefly reviewed.