Ventricular function before and after mitral valve replacement.

To evaluate right ventricular function following mitral valve replacement, we studied 84 patients with isolated mitral valve disease with the use of first-pass radionuclide angiography before, 1 week after, and up to 1 year after operation. The right ventricular ejection fraction for the entire group improved from 29% +/- 11% to 43% +/- 10% (p less than 0.001) at 1 week. This increase was maintained at 3 months (41% +/- 10%) and up to year after operation (40% +/- 12%). The improvement was found not to be influenced by either the type of valvular lesion or the presence and/or level of pulmonary hypertension. When the patients were grouped according to the type of prosthetic valve placed at operation, the right ventricular ejection fraction increased in all patients within 1 week of operation, with sustained improvement at 3 months postoperatively. Thereafter, it began to decline in patients receiving a Carpentier bioprosthesis while being maintained in those patients who received disc valves. Further analysis revealed that those patients who receiving the larger Carpentier bioprostheses had a greater deterioration of right ventricular function than those receiving the smaller Carpentier valves. Left ventricular function in the entire group was normal preoperatively (62% +/- 16%) and was unchanged at 1 week (60% +/- 16%) and a 1 year (59% +/- 16%) after operation.