Using transmitral flow velocity and left ventricular ejection flow velocity, we measured left ventricular inflow volume (LVIV) and left ventricular outflow volume (LVOV) by pulsed Doppler echocardiography in 73 patients who had mitral valve regurgitation (MR), aortic valve regurgitation (AR), or no valvular regurgitation. Doppler-determined regurgitant volume (DOPRV), Doppler-determined regurgitant fraction (DOPRF), total stoke volume, and forward stroke volume were calculated to compare the severity assessed by angiographic scoring and the regurgitant fraction determined by radionuclide angiography (RIRF). In 17 patients with MR, LVIV (84.4 +/- 20.4 ml) was significantly greater (p less than 0.01) than LVOV (52.5 +/- 15.7 ml). LVOV, which is equivalent to forward stroke volume, was lower in patients with MR (52.2 +/- 15.7 ml) than in normal subjects (67.0 +/- 15.7 ml). In 15 patients with AR, LVOV (121.7 +/- 61.1 ml) was significantly greater (p less than 0.01) than LVIV (75.1 +/- 28.1 ml) and LVOV, which is equivalent to total stroke volume, was greater in patients with AR (121.7 +/- 61.1 ml) than in normal subjects (64.0 +/- 14.4 ml). DOPRF correlated with RIRF (r = 0.79, p less than 0.01, n = 11). DOPRV (mild: 10.5 +/- 8.5 ml; moderate: 28.8 +/- 13.6 ml; severe: 74.5 +/- 36.7 ml) and DOPRF (mild: 13.7% +/- 11.5%; moderate: 33.1% +/- 14.2%; severe: 52.6% +/- 15.3%) increased markedly with the severity of regurgitation as assessed by cineangiography. In AR, total stroke volume influenced both forward stroke volume and regurgitant volume, and in MR, regurgitant volume influenced both total stroke volume and forward stroke volume. Total stroke volume in AR and regurgitant volume in MR may play a key role in valvular regurgitation.