LEFT ATRIAL CONTRIBUTION TO LEFT-VENTRICULAR FILLING IN PATIENTS WITHMITRAL-STENOSIS - COMBINED ANALYSIS OF TRANSMITRAL AND PULMONARY VENOUS FLOW VELOCITIES

We recorded transmitral and pulmonary venous flow velocities using tra nsthoracic continuous-wave and transesophageal pulsed Doppler echocard iography respectively, in 36 patients with mitral stenosis who were in sinus rhythm to investigate the left atrial contribution to left vent ricular filling in mitral stenosis. The mitral valve area was determin ed by transthoracic two-dimensional short-axis echocardiography. Patie nts were classified as having mild stenosis (greater than or equal to 1.5 cm(2), n = 17) or moderate stenosis ( < 1.5 cm(2), n = 29). The me an pulmonary capillary wedge pressure and left atrial maximal diameter were significantly larger, and left atrial volume change during atria l contraction was significantly smaller in the moderate group than in the mild group. The percent left atrial contribution to left ventricul ar filling, estimated from the transmitral flow velocity, the peak atr ial systolic velocity, and the percent ratio of left atrial systolic r egurgitation to left atrial filling, estimated from the pulmonary, ven ous flow velocity, were significantly lower in the mode. ate group tha n in the mild group. The percent left atrial contribution to left vent ricular filing, the peak atrial systolic velocity, and the percent rat io of left atrial systolic regurgitation to left atrial filling were p ositively correlated with the mitral valve area and negatively correla ted with the mean pulmonary capillary wedge pressure. These results su ggest that the left atrial contribution to left ventricular filling in patients with mitral stenosis in sinus rhythm decreases as the severi ty of valve stenosis increases, and that analysis of the atrial systol ic waves of the transmitral and pulmonary venous flow velocities provi des important information for evaluation of left atrial systolic perfo rmance in patients with mitral stenosis. (ECHOCARDIOGRAPHY, Volume 15, January 1998).