Effects of mitral regurgitation on pulmonary venous flow and left atrial pressure: An intraoperative transesophageal echocardiographic study

Objectives and Background. Pulmonary venous flows recorded by pulsed wave Doppler transesopnageal echocardiography examination can be used to assess the severity of mitral regurgitation. Pulmonary venous flows are also related to left atrial pressures; however, the determinants of these flows have yet to be characterized in the presence of mitral regurgitation. Methods. We simultaneously recorded intraoperative pulmonary venous flows by transesophageal echocardiography and left atrial pressures by direct left atrial puncture in 16 patients with different grades of mitral regurgitation: 2+ (n = 5), 3+ (n = 4) and 4+ (n = 7). Pulmonary venous peak systolic and diastolic flow velocities and peak reversed systolic flow velocities were compered with left atrial pressure aand vwaves, a-xand v-ydescent values and left atrial volumes. Results. Pulmonary venous systolic to diastolic flow ratios correlated with decreases in left atrial pressure av ratios and with increases in the vwaves of patients with higher grades of mitral regurgitation. Univariate analysis revealed that the best determinants of the pulmonary venous systolic to diastolic low ratio were the left atrial pressure vwave (r = −0.76), the v-ydescent value (r = −0.73) and the av ratio (r = 0.71). Lower correlations were found for left atrial end-systolic (r = −0.48) and end-diastolic (r = −0.42) volumes. Reversed systolic flow was present in patients with 4+ mitral regurgitation, despite left atrial enlargement. Conclusions. Pulmonary venous flow can be used to assess the severity of mitral regurgitation and reflects the effects of mitral regurgitation severity on the left atrial pressure aand vwaves.