ABSTRACT
Aim of this study was to evaluate right ventricular performance in patients with mitral stenosis and its modification by balloon valvuloplasty. Right ventricular volumes of 24 patients with postrheumatic mitral stenosis were determined by thermodilution 1 or 2 days before and 1 or 2 days after valvuloplasty. Right ventricular ejection fraction at rest was 43 (36-47)% (median and interquartile range). Right ventricular end-diastolic volume was 100 (86-119) ml/m2. Supine bicycle exercise (50 Watt) reduced right ventricular ejection fraction to 30 (29-37)% (P < 0.0001) and increased right ventricular end-diastolic volume to 124 (112-141) ml/m2 (P < 0.0001). At rest, right ventricular ejection fraction correlated inversely with pulmonary vascular resistance (r = -0.64, P < 0.0001), while no significant correlation with mitral valve area was 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 correlated inversely with the value of this parameter before valvuloplasty (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 commissurotomy, was reestablished by the procedure. In conclusion, at the here investigated stage of mitral stenosis right ventricular function is reversibly impaired. This is predominantly caused by the hemodynamic consequences of the valvular defect and not by an impairment of right ventricular myocardial function.
Subject(s)
Catheterization , Mitral Valve Stenosis/complications , Ventricular Dysfunction, Right/therapy , Ventricular Function, Right , Adult , Aged , Cardiac Catheterization , Exercise Test , Female , Heart Rate , Hemodynamics , Humans , Male , Middle Aged , Mitral Valve Stenosis/physiopathology , Mitral Valve Stenosis/therapy , Regression Analysis , Statistics, Nonparametric , Stroke Volume , Thermodilution , Ventricular Dysfunction, Right/etiologyABSTRACT
UNLABELLED: Postrheumatic mitral stenosis might cause impairment of right ventricular (RV) function due to both an increase in RV afterload and rheumatic myocardial disease. Therefore, we investigated in 19 patients with postrheumatic mitral stenosis and sinus rhythm right ventricular volumes and hemodynamics by a computerized thermodilution catheter during rest and supine bicycle exercise. In 14 patients the investigation was repeated within 2 days after balloon mitral valvuloplasty. Resting RV ejection fraction was decreased (43 (15-53)%, median (range)) and correlated significantly with RV end-systolic volume index (r = -0.90), stroke volume index (r = 0.77), RV end-diastolic volume index (r = -0.76), heart rate (r = -0.69), pulmonary artery resistance (r = -0.69), and mean pulmonary artery pressure (r = -0.68). RV end-diastolic volume index was 107 (81-200) ml/m2. Exercise induced a decrease of RV ejection fraction to 36 (13-48)% at 50 Watt (p < 0.001), while it increased RV end-diastolic volume index to 131 (78-231) ml/m2 (p < 0.001). Balloon mitral valvuloplasty improved RV ejection fraction at rest from 41 (15-47)% to 48 (39-55)% (p < 0.005) and from 30 (13-46)% to 43 (27-56)% during exercise (p < 0.005). The increase of RV ejection fraction after valvuloplasty was caused by an increase in stroke volume, but not by a reduction in RV end-diastolic volume. CONCLUSION: Depending on the increased RV afterload, RV function is markedly depressed in mitral stenosis. An immediate and almost complete improvement of RV function occurs with the reduction of RV afterload after balloon mitral valvuloplasty.(ABSTRACT TRUNCATED AT 250 WORDS)
