EFFECT OF MITRAL REGURGITATION ON PULMONARY VENOUS VELOCITIES DERIVED FROM TRANSESOPHAGEAL ECHOCARDIOGRAPHY COLOR-GUIDED PULSED DOPPLER IMAGING

The effect of mitral regurgitation on pulmonary venous flow velocity was studied in 66 patients undergoing transesophageal echocardiography. Nine patients were studied intraoperatively before and after surgery, so that 75 pulmonary venous flow tracings were analyzed. Fifty-four patients had no significant (0 to 1+) mitral regurgitation and 21 had significant (2 to 3+) mitral regurgitation. Comparison of both groups revealed significant differences in the pulmonary venous flow pattern. In patients with no significant mitral regurgitation, the peak systolic velocity was higher (55 +/- 16 vs. -4 +/- 16 cm/s; p < 0.0001) and the peak diastolic velocity was lower (43 +/- 13 vs. 59 +/- 17 cm/s; p < 0.01) when compared with values in patients with significant mitral regurgitation. Consequently, the peak systolic/diastolic velocity ratio was significantly higher in the patients without significant mitral regurgitation (1.4 +/- 0.5 vs. 0.4 +/- 1.3; p < 0.0001). The same trend was noted with respect to the systolic and diastolic velocity integrals. As the degree of mitral regurgitation increased, the peak diastolic velocity and diastolic velocity integral increased, whereas the peak systolic velocity and systolic velocity integral decreased. In patients with severe mitral regurgitation, the systolic flow became reversed (retrograde). The sensitivity of reversed systolic flow for severe mitral regurgitation was 90% (9 of 10), the specificity was 100% (65 of 65), the positive predictive value was 100% (9 of 9), the negative predictive value was 98% (65 of 66) and the predictive accuracy was 99% (74 of 75). Multivariate regression analysis including the variables age, heart rate, left atrial size, cardiac rhythm and left ventricular ejection fraction identified the degree of mitral regurgitation as the only independent predictor of pulmonary venous peak systolic velocity (F = 80; p < 0.0001). Thus, mitral regurgitation significantly modifies the pulmonary venous flow pattern as assessed by transesophageal echocardiography. The occurrence of reversed flow during systole is a highly sensitive and specific index of severe mitral regurgitation.