[Pressure-flow relations of artificial valves in the mitral position (author's transl)].

Hemodynamic studies in pts. with Starr-Edwards disc valves (SE), Lillehei-Kaster valves (LK) and normal mitral valves (N) were performed to compare pressure gradient (deltaP) and volume flow (V). Therefore, synchronous pressure-volume measurements at a diastolic filling time of 500 ms and 250 ms were done. The results show that deltaP in SE valves is much higher than in LK-valves, but this exists only at the beginning of volume acceleration whereas at the end of diastolic time deltaP is similar to that of LK valves. In normal mitral valves initial pressure gradients are also present. Maximum volume flow in SE valves occurs at the end of diastole, but in normal mitral valves and in LK valves, however, it is reached already at the beginning. The studies showed a substantial obstacle to volume flow in SE-disc valves while LK-valves are similar to normal mitral valves.