Abstract
To elucidate the Doppler derived aortic peak flow velocity profiles and their relation to valve size in low profile mechanical prosthesis with and without postoperative aortic regurgitation, 49 patients with normal functioning low profile mechanical valves (group 1–19 patients with aortic regurgitation, and group 2-30 patients without aortic regurgitation) were evaluated. Aortic peak flow velocity and aortic mean flow velocity were significantly higher in group 1 compared to those in group 2. Aortic peak flow velocity had an inverse linear relation with valve size in group 1 (r = –0.75, p < 0.05) and group 2 (r = –0.72,p < 0.01), and aortic peak flow velocity was significantly higher in group 1 at every valve size (p < 0.01). On the otaher hand, there were no differences in left ventricular end-diastolic dimension, left ventricular end-systolic dimension,and left ventricular fractional shortening between the two groups. Thus,although postoperative mild aortic regurgitation in low profile mechanical prostheses may not induce clinical problems, it had a significant effect on the normal value of aortic flow velocity profiles.