Assessment of the closing dynamics in Bjork-Shiley mitral prostheses by digital echocardiography: in vitro validation

Some Bjork-Shiley Convexo-Concave (BSCC) mitral prostheses may experience outlet strut fracture (OSF) caused by material fatigue which has been shown to be linearly related to disc closing velocity (DCV). The authors examine whether DCV could be estimated by echocardiography (echo) by means of measurement of disc closing time (DCT). 40 hydrodynamic states were simulated in an in vitro model. A velocity sensor mounted on the sewing ring to provided the DCV. DCT was define as the time from the onset of disc closure indicated by digitally stored M-mode echo tracings to the first closure sound as assessed by phonocardiography. DCV (y) was highly correlated inversely with DCT (x), y=-0.16x+57.7, r=-0.88, p<0.001, and positively with disc closing pressure (r=0.94, p<0.001). When clinically validated, echo may be useful to identify patients with potential risk of OSF.<
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