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Doppler echocardiographic study of the bjork-shiley integral monostrut aortic valve prosthesis: Data from 106 stable patients

Abstract:

In order to determine the normal range of the Doppler hemodynamic characteristics of the Bjork-Shiley Monostrut aortic prostheses, maximum and mean Doppler gradients, prosthetic valvular areas using the continuity equation, and degree of aortic regurgitation were measured in 106 stable patients with these valves. The maximum and mean Doppler gradients were in the range 9.5-51 mmHg (28.9 ± 11) and from 2-24 mmHg (12.7 ± 5.2), respectively. Maximum Doppler gradients > 45 mmHg and mean Doppler gradients > 20 mmHg occurred only in sizes 23 or smaller. No patient had a Doppler mean gradient > 25 mmHg. We found significant differences between size 25 and 27 (p < 0.01) and between size 21 and 25 (p < 0.01), but not between 19, 21 and 23, nor between 23 and 25 sizes. There were significant differences in Doppler-determined prosthetic valvular areas between successive valve sizes. The correlation coefficient between the prosthetic size and the echo-Doppler-determined valvular area was 0.82 (SEE = 22), using a linear equation. Mild aortic regurgitation was demonstrated in 25 cases (24%). It is the authors' conclusion that high-pressure gradients can be observed in the smallest sizes of the Bjork-Shiley Monostrut aortic prostheses. Mild aortic regurgitation is a common finding. The values reported are suggested as a reference for comparison in the case of suspected Bjork-Shiley valve dysfunction.