Clinical significance and hemodynamic correlates of the third heart sound gallop in aortic regurgitation. A guide to optimal timing of cardiac catheterization.

The hemodynamic and clinical data of 42 patients with chronic significant aortic regurgitation and 31 normal subjects were examined. Of the patients with aortic regurgitation, 28 had a third heart sound (S3) gallop and 14 did not. There was no significant difference in the severity of regurgitation between the patients with or without an S3 gallop. However, all patients with an S3 gallop had an abnormality increased left ventricular residual volume and depressed contractile state. These findings were supported by the hemodynamic data of two patients who underwent cardiac catheterization before and after the development of an S3 gallop. We conclude that the S3 gallop in patients with chronic AR reflects left ventricular dysfunction, rather than more severe degrees of regurgitation per se, and may therefore be useful for selecting patients for cardiac catheterization and consideration for prosthetic aortic valve replacement.