[Hemodynamics after mitral valve replacement with Starr-Edwards, Björk-Shiley and Lillehei-Kaster protheses (author's transl)].

After mitral valve replacement hemodynamic abnormalities persist. These abnormalities were studied 1 year postoperatively. In 50 randomized patients; 15 with Starr-Edwards (SEM), 15 with Lillehei-Kaster (LKM) and 20 with Björk-Shiley (BSM) prostheses at rest and during exercise. Simultaneously were determined: pulmonary arterial pressure, left atrial pressure, left ventricular enddiastolic pressure, mean diastolic pressure gradient across the prostheses, cardiac index, stroke volume index, valve orifice area, and ejection fraction. The results show an important stenosis by the prostheses leading to high pressure increase in pulmonary artery and left atrium during excercise. This stenosis depends on valve size and type. Björk-Shiley tilting disc valves show the best hemodynamic results. This may be due to the most favourable ratio between internal and external diameter. Starr-Edwards prostheses with identical sizes show the most identical results if compared to each other. Therfore we suggest that Starr-Edwards prostheses open completely in every case. However, there is an important pressure gradient caused by the small internal diameter. Lillehei-Kaster pivoting disc valves reach surprisingly small functional valve areas. This may be caused by an incomplete opening of the disc.