The study of the third heart sound in relation to the left ventricular filling and wall movement by echocardiography.

The left ventricular filling and wall movement were investigated in subjects with a third heart sound or ventricular gallop by echocardiography. Nine patients with ventricular gallop, who had left ventricular volume overload disease, and 6 normal subjects with a third heart sound had higher normalized peak rate of increase of the left ventricular dimension (peak dD/dT/D) than 10 normal subjects without a third heart sound (p less than 0.01). The normalized lengthening rate in the rapid filling phase was also higher in patients with ventricular gallop than in normal subjects without a third heart sound (p less than 0.05). The time from the second heart sound to peak dD/dT/D and rapid filling time did not show statistically significant values between subjects with ventricular gallop or a third heart sound and those without a third heart sound. These results suggest that higher peak filling, larger filling volume in the rapid filling phase and more abrupt cessation of the outward movement of the left ventricular wall may be a cause of the production of ventricular gallop in patients with left ventricular volume overload and of the physiological third heart sound.