RIGHT-VENTRICULAR FUNCTION BEFORE AND AFTER PERCUTANEOUS BALLOON MITRAL VALVULOPLASTY

Aim of this study was to evaluate right ventricular performance in pat ients with mitral stenosis and its modification by balloon valvuloplas ty. Right ventricular volumes of 24 patients with postrheumatic mitral stenosis were determined by thermodilution 1 or 2 days before and 1 o r 2 days after valvuloplasty. Right ventricular ejection fraction at r est was 43 (36-47)% (median and interquartile range). Right ventricula r end-diastolic volume was 100 (86-119) ml/m(2). Supine bicycle exerci se (50 Watt) reduced right ventricular ejection fraction to 30 (29-37) % (P<0.0001) and increased right ventricular end-diastolic volume to 1 24 (112-141) ml/m(2) (P<0.001). At rest, right ventricular ejection fr action correlated inversely with pulmonary vascular resistance (r=-0.6 4, P<0.001), while no significant correlation with mitral valve area w as found. Valvuloplasty increased right ventricular ejection fraction at rest to 48 (44-50)% (P<0.005), and during exercise to 42 (38-45)% ( P<0.0001). This improvement of right ventricular ejection fraction cor related inversely with the value of this parameter before valvuloplast y (r=-0.88, P<0.0001) and with the gain in stroke volume (r=0.57, P<0. 01). The right ventricular function curve, disturbed before commissuro tomy, was reestablished by the procedure. In conclusion, at the here i nvestigated stage of mitral stenosis right ventricular function is rev ersibly impaired. This is predominantly caused by the hemodynamic cons equences of the valvular defect and not by an impairment of right vent ricular myocardial function. Copyright (C) 1997 Elsevier Science Irela nd Ltd.