Globits S, Rödler S, Moritz A, Schreiner W, Pacher R, Glogar D, Wolner E
2nd Department of Internal Medicine, University of Vienna, Austria.
J Heart Valve Dis. 1993 Nov;2(6):665-70.
In order to define normal flow characteristics at mid-term follow up, prospective Doppler echocardiographic studies were performed in 145 patients (mean age 49.3 years) with Duromedics-Edwards bileaflet valve prostheses (76 aortic, 55 mitral and 14 double aortic and mitral) at a mean interval of 5.2 years following operation. All patients had clinically normal prosthetic valve function and no clinical or radiographic signs of heart failure. None of the patients had severely impaired left ventricular function as assessed by cross sectional 2D echocardiography. Mean peak velocity across prostheses in the aortic position was 2.8 +/- 0.5 m/sec, corresponding to a calculated instantaneous peak pressure gradient of 31.4 +/- 10.2 mmHg. Gradients varied inversely to valve size, although differences were significant only when comparing the 19mm and 21mm versus the 27mm valve (p < 0.05). In the mitral position the mean of peak velocity was 1.8 +/- 0.3 m/sec and pressure half time was 102 +/- 14 msec, representing a calculated mean orifice size of 2.2 +/- 0.5 cm2, with no significant difference between valves of different sizes. Paravalvular regurgitation was more common in the aortic than in mitral position (39% vs. 4%, p < 0.05), although in all cases it was mild (range less than one centimeter from prosthesis ring) and clinically insignificant. We conclude that normally functioning DE valve prostheses have a predictable range of Doppler echocardiographic parameters, although the individual variability of pressure gradients and effective valve area (in mitral valves) has to be emphasized. Nevertheless, the Duromedics Edwards valve shows good hemodynamic properties at mid-term follow up.
