Three-dimensional dynamics of the canine mitral annalus during ischemic mitral regurgitation

Abstract

Background. It has been suggested that ischemic mitral regurgitation results, at least in part, from generalized end-systolic mitral annulus (MA) dilatation, but the role of the MA is incompletely understood and the segmental dynamics of the MR during left ventricular ischemia have not been described. Methods. We used radiopaque markers and simultaneous biplane videofluoroscopy to measure three-dimensional in vivo lengths of eight MA segments in 7 sedated dogs before and after induction of ischemic MB (produced by circumflex coronary artery balloon occlusion and verified by Doppler echocardiography). As viewed from the left atrium, the MA segment between markers 1 and 2 (S12) was defined as ..