We evaluated late the in vivo hemodynamic function of Björk-Shiley prostheses in 15 patients who had undergone aortic valve replacement. Cardiac catheterization was performed at rest and during exercise in 5 pts with size 19·21·23 valves (Group I) in an average of 45 months, and in 10 pts with size 25·27·29 valves (Group II) in an average of 10 months after operation.
The left ventricle was catheterized by the transseptal technique postoperatively.
The average aortic mean systolic gradient in G-I was 25mmHg at rest and 46mmHg during exercise. It in G-II was 5mmHg at rest and 6mmHg during exercise.
The average calculated orifice area in G-I was 1.14cm2 at rest and 1.27cm2 during exercise. And it in G-II was more than 2.0cm2.
Left ventricular function such as cardiac index, end-diastolic volume and ejection fraction was unchanged for the group. However, LVEDP in 2 pts in G-I elevated abnormally at rest. Thus, patients in G-I had functional
