Determination of regurgitant fraction in isolated mitral or aortic regurgitation by pulsed Doppler two-dimensional echocardiography.

Measurements of mitral and aortic valve flows were obtained with two-dimensional Doppler echocardiography in 25 patients with isolated mitral (n = 19) or aortic (n = 6) regurgitation and regurgitant fraction was calculated as the difference between the two flows divided by the flow through the regurgitant valve. Results were compared with measurements of regurgitant fraction determined by combined left ventricular angiography and thermodilution. Regurgitant fraction averaged 56 +/- 18% (range 19 to 79) by Doppler echocardiography and 48 +/- 17% (range 13 to 72) by angiography. A significant correlation was observed between the two methods (r = 0.91; SEE = 7%). In contrast, no significant correlation was found between regurgitant fraction measured by either method and the angiographic 1+ to 4+ qualitative classification of regurgitation. Doppler echocardiography appears to be an accurate method for the non-invasive quantification of severity of regurgitation in isolated left-sided valve lesions.