Immediate effects of mitral valve replacement on left ventricular functionand its determinants

Patients undergoing mitral valve surgery are at risk of left ventricular fa ilure in the immediate post-operative period. In order to understand better the mechanisms of post-operative haemodynamic instability, we used transoe sophageal echocardiography to assess the immediate response of the left ven tricle to mitral valve replacement for mitral regurgitation or stenosis. A decrease in left ventricular preload, despite adequate filling pressures, w as common to both groups and suggests the presence of diastolic dysfunction . A marked impairment in global systolic pump function was observed only in the regurgitation group and correlated with the left ventricular afterload . Transoesophageal echocardiography provides valuable information on the in dividual changes in left ventricular function and its determinants after mi tral valve replacement that are not reflected by haemodynamic measurements.