Doppler Echocardiographic Determination of Geometric Orifice Areas in Mechanical Aortic Valve Prostheses

In 63 St. Jude bileaflet and 34 Bjoerk-Shiley tilting disk aortic valve prostheses, Doppler continuity areas were compared to their corresponding geometric areas defined by the opening angle of the occluders. Continuity areas correlated significantly with geometric areas in Bjoerk-Shiley (p = 0.68) and St. Jude prostheses (p = 0.86). Differences between continuity and geometric areas were greater in St. Jude than in Bjoerk-Shiley valves (0.87 ± 0.45 cm2 vs. 0.06 ± 0.47 cm2, p