The value of assessing pulmonary venous flow velocity for predicting severity of mitral regurgitation: A quantitative assessment integrating left ventricular function

Although alteration in pulmonary venous flow has been reported to relate to mitral regurgitant severity, it is also known to vary with left ventricula r (LV) systolic and diastolic dysfunction. There are few data relating pulm onary venous flow to quantitative indexes of mitt-al regurgitation (MR). Th e object of this study was to assess quantitatively the accuracy of pulmona ry venous flow for predicting MR severity by using transesophageal echocard iographic measurement in patients with variable LV dysfunction. This study consisted of 73 patients undergoing heart surgery with mild to severe MR. R egurgitant orifice area (ROA), regurgitant stroke volume (RSV), and regurgi tant fraction (RF) were obtained by quantitative transesophageal echocardio graphy and proximal isovelocity surface area. Both left and right upper pul monary venous flow velocities mere recorded and their patterns classified b y the ratio of systolic to diastolic velocity: normal (greater than or equa l to 1), blunted (<1), and systolic reversal (<0). Twenty-three percent of patients had discordant patterns between the left and right veins. When the most abnormal patterns either in the left or right vein were used for anal ysis, the ratio of peak systolic to diastolic now velocity vp-as negatively correlated with ROA (r = -0.74, P < .001), RSV (r = -0.70, P < .001), and RP (r = -0.66, P < .001) calculated by the Doppler thermodilution method;va lues were r = -0.70, r = -0.67, and r = -0.57, respectively (all P < .001), for indexes calculated by the proximal isovelocity surface area method. Th e sensitivity, specificity, and predictive values of the reversed pulmonary venous now pattern for detecting a large ROA (0.3 cm(2)) were 69%, 98%, an d 97%, respectively. The sensitivity, specificity, and predictive values of the normal pulmonary venous flow pattern for detecting a small ROA (<0.3 c m(2)) were 60%, 96%, and 94%, respectively. However, the blunted pattern ha d low sensitivity (22%), specificity (61%), and predictive values (30%) for detecting ROA of greater than 0.3 cm(2) with significant overlap with the reversed and normal patterns. Among patients with the blunted pattern, the correlation between the systolic to diastolic velocity ratio was worse in t hose with LV dysfunction (ejection fraction <50%, r = 0.23, P > .05) than i n those with normal LV function (r = -0.57, P < .05). Stepwise linear regre ssion analysis showed that the peak systolic to diastolic velocity ratio wa s independently correlated with RF (P < .001) and effective stroke volume ( P < .01), with a multiple correlation coefficient of 0.71 (P < .001). In co nclusion, reversed pulmonary venous now in systole is a highly specific and reliable marker of moderately severe or severe MR with an ROA greater than 0.3 cm(2), whereas the normal pattern accurately predicts mild to moderate MR Blunted pulmonary venous now can be seen in all grades of MR with low p redictive value for severity of MR, especially in the presence of LV dysfun ction. The blunted pulmonary venous now pattern must therefore be interpret ed cautiously In clinical practice as a marker for severity of MR.