Left Atrial Distensibility and Left Ventricular Filling Pressure in Acute Versus Chronic Severe Mitral Regurgitation

Echocardiograms and left ventricular (LV) filling pressure were obtained from 95 patients with chronic severe mitral regurgitation (MR) and 16 patients with acute severe MR. All patients underwent catheterization for preoperative examinations and LV filling pressure measurements. A total of 52 age-, gender- and co-morbidity-matched patients with negative coronary angiographic results served as the controls. Echocardiography, including assessment of left atrial (LA) distensibility, was performed simultaneously. LA distensibility correlated logarithmically with the LV filling pressure. However, the early-diastolic mitral inflow velocity divided by the early-diastolic mitral annular velocity (mitral E/E′) correlated linearly with the LV filling pressure. Bivariate correlation analysis revealed that LV filling pressure correlated positively with the maximum and minimum indexed LA volume, as well as the E/E′, but the LV filling pressure correlated negatively with LA distensibility, LA ejection fraction, and LV ejection fraction. However, the MR regurgitation volume was associated only with the maximum and minimum indexed LA volume. Receiver operating characteristic curve analysis indicated that LA distensibility was not inferior to E/E′ for identifying a LV filling pressure >15 mm Hg. However, to identify acute severe MR, LA distensibility was superior to E/E′. In conclusion, LA distensibility, as is E/E′, is a valuable diastolic parameter. In patients with severe MR, it offers adequate power to assess the LV filling pressure and to identify acute severe MR.