title: Doppler echocardiographic determination of geometric orifice areas in mechanical aortic valve prostheses.
abstract: 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 < 0.0001). Exclusion of patients with atrial fibrillation, with a postoperative interval of less than 1 year or valve sizes of 19 and 21 mm did not change the results. Thus, underestimation of geometric areas is present in the St. Jude bileaflet aortic valves, while geometric and continuity areas are not significantly different in Bjoerk-Shiley prostheses. These results are attributable to the effect of valve-type-dependent velocity profiles.
authors.affiliation: Department of Cardiology, University of Erlangen-Nuremberg, Germany.
authors.forename: K H
authors.initials: KH
authors.lastname: Henneke
authors.forename: G
authors.initials: G
authors.lastname: Pongratz
authors.forename: M
authors.initials: M
authors.lastname: Pohlmann
authors.forename: K
authors.initials: K
authors.lastname: Bachmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000601:surgery*; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D002304:Cardiac Pacing, Artificial; D015150:Echocardiography, Doppler; D005260:Female; D006350:Heart Valve Prosthesis; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011474:Prosthesis Design