Sequential hemodynamic studies following mitral fascia lata valve replacement.

Sequential hemodynamic studies were performed at mean intervals of 6 and 38 months following mitral valve replacement in 10 patients who had angiographically competent fascia lata valves and in whom preoperative hemodynamic studies were available. The cardiac index did not change significantly during postoperative studies as compared with the preoperative values, and its response in relation to oxygen uptake during exercise remained impaired. The mean pulmonary wedge and pulmonary artery pressures showed significant reduction at the first and the second postoperative studies, both at rest and during exercise. Progressive reduction in the pulmonary vascular resistance occurred in patients with high initial values, although the group mean did not alter significantly. The mean diastolic gradient across the mitral fascial valves averaged 8.1 +/- 1.3 mm Hg at rest rising to 22.5 +/- 2.4 mm Hg during exercise (P less than 0.001), and the calculated mitral valve area was 1.9 +/- 0.22 cm2 at rest and 2.36 +/- 0.3 cm2 during exercise (P less than 0.02). This study indicates that the insertion of stented mitral fascia lata valves results in significant hemodynamic improvement, which is maintained at least for 3 years after surgery, in patients with competent valves. However, a degree of obstruction to the forward flow is apparent especially during exercise, despite the central flow design of the valve.