Observations on the Delayed First Heart Sound in Mitral Stenosis and Hypertension

Abstract

The measurement of the time between the onset of ventricular depolarization and the first heart sound, the Q-1 interval, has been employed in the phonocardiographic evaluation of patients with rheumatic heart disease. Prolongation of this interval has been noted frequently in patients with mitral stenosis and may be used as evidence in weighing the advisability of operation. In the present study, delayed appearance of the first heart sound was often noted in patients with hypertensive vascular disease as well. The mechanism for these changes as well as their significance in the phonocardiographic evaluation of patients with combined valvular disease and hypertension is discussed.