Biplane transesophageal color-flow Doppler imaging in assessing severity of mitral regurgitation: influence of hemodynamic circumstances and mechanism of regurgitation.

OBJECTIVE: To determine the value of biplane transesophageal echocardiography in the assessment of severity of mitral regurgitation compared with left ventricular angiography. DESIGN: Prospective study of consecutive patients. SETTING: Two university hospitals, one community hospital. PARTICIPANTS: Thirty-seven patients with angiographically proven mitral regurgitation. INTERVENTION: Transthoracic and biplane transesophageal echocardiography. In 19 patients, transesophageal echocardiography was performed during general anesthesia. MEASUREMENTS AND MAIN RESULTS: The largest mitral regurgitation jet area and longest jet as obtained with Doppler color-flow mapping from transthoracic and biplane transesophageal echocardiography and pulsed-Doppler pulmonary venous flow characteristics. Sensitivity and 100-minus-specificity were plotted to constitute receiver operating characteristics (ROC) curves. Areas under ROC curve for transverse, longitudinal, and biplane jet area were 0.77, 0.75, and 0.81, and for jet length, 0.82, 0.84, and 0.88, respectively; this was for biplane jet area in conscious patients; 0.99 compared with 0.72 in anesthetized patients (p < 0.05). CONCLUSIONS: Biplane measurements identified severe mitral regurgitation slightly more reliably than the transverse or longitudinal measurements alone. In conscious patients, jet area was an excellent test for estimating severity of mitral regurgitation. In anesthetized patients, a combination of biplane jet area and length and of systolic pulmonary venous flow reversal accurately predicted angiographic severity of mitral regurgitation. In anesthetized patients, the optimal cut-off value for jet area to distinguish between moderate and severe mitral regurgitation was lower than in conscious patients. In the total population, regardless of hemodynamic and technical variations, a combination of biplane jet area and length and of systolic pulmonary venous flow reversal accurately predicted the severity of mitral regurgitation.