Ratio of early transmitral velocity to lateral mitral annular early diastolic velocity has the best correlation with wedge pressure following cardiac surgery

Background Although previous investigators reported that mitral annular velocity predicts mean pulmonary capillary wedge pressure (PCWP), it is unknown whether the lateral or septal mitral annular velocity more faithfully predicts PCWP after cardiac surgery. Methods and Results To assess the effect of cardiac surgery on the predictive values for PCWP by measuring mitral annular velocity, 52 consecutive patients undergoing cardiac surgery were studied. All patients underwent transthoracic echocardiography and right-sided cardiac catheterization both before and after surgery. The peak early diastolic velocity of transmitral flow (E) was measured by pulsed-wave Doppler and the peak early diastolic velocities of the lateral (LEa) and septal (SEa) mitral annulus by pulsed-wave tissue Doppler imaging. The ratios of E to LEa (E/LEa) and SEa (E/SEa) were calculated. Immediately after echocardiography, PCWP was measured using a balloon-tipped pulmonary artery catheter. After surgery, LEa was significantly increased (6.4 +/- 2.7 vs 8.6 +/- 3.3 cm/s, p < 0.001), but SEa was unchanged (6.0 +/- 2.5 vs 5.5 +/- 2.3 cm/s, p=0.09). E/LEa correlated well with PCWP both before and after surgery (r=0.79 and r=0.69, respectively, p < 0.001). Although E/SEa correlated well before surgery (r=0.67, p < 0.001), it correlated only weakly after surgery (r=0.44, p < 0.01). Conclusions E/LEa has the best correlation with PCWP both before and after cardiac surgery and may be more useful than E/SEa in the noninvasive estimation of PCWP.