CLINICAL AND HEMODYNAMIC-RESULTS AFTER COMBINED AORTIC AND MITRAL-VALVE REPLACEMENT WITH THE LILLEHEI-KASTER PIVOTING DISK VALVE

Combined mitral and aortic valve replacement with the Lillehei-Kaster pivoting disc valve prosthesis was performed in 23 patients. Hospital mortality rate was 8.3%. Postoperative clinical and hemodynamic studies were performed after a mean follow-up period of 24.4 mo. Replacement of both valves resulted in marked symptomatic and hemodynamic improvement with normal or nearly normal resting value of cardiac output, pulmonary arterial pressure and pulmonary vascular resistance while left ventricular end-diastolic pressure (LVEDP) increased significantly. The rise in left ventricular end-diastolic pressure is most probably related to the simultaneous rise in cardiac output (Starling mechanism), reflecting the severity and irreversibility of the underlying myocardial disease. Most patients also had systolic gradient across the aortic prosthesis, and diastolic gradient across the mitral prosthesis. The gradients across the mitral prosthesis were approximately the same as those after single valve replacement, and the pressure gradients across the aortic prosthesis were somewhat smaller than previously reported. Angiographic studies of aortic valve movement indicated that the opening angle of the disc was .apprx. 60.degree., and less than predicted by valve specifications.