Movement of mitral valve cusps in relation to first heart sound and opening snap in patients with mitral stenosis.

Doubt has been cast upon the valvular origin of the first heart sound since the finding of a delay between the cross-over of the ventricular and atrial pressure tracings and the sound attributed to closing ofthe corresponding atrio-ventricular valve. There is a similar delay after the left ventricular pressure falls below that in the left atrium before the occurrence of the opening snap in mitral stenosis. During the routine investigation of patients with mitral stenosis the movements of the mitral valve have been recorded by selective cine-angiocardiography simultaneously with the heart sounds.