Annuloplasty Rings Designed To Treat Functional/Ischemic Mitral Regurgitation Do Not Alter Left-Ventricular Dimensions In The Acutely Ischemic Ovine Heart

Introduction: Annuloplasty rings to treat functional/ischemic mitral regurgitation (FMR/IMR) include a greater downsizing of the septal-lateral (S-L) than the commissure-commissure (C-C) mitral annular dimension. This design is not only intended to maximize mitral leaflet coaptation, but also to reshape the dilated, spherical left ventricle (LV). Hypothesis: Disease-specific FMR/IMR ring types reduce left-ventricular S-L, but not C-C dimensions during acute myocardial ischemia in the beating ovine heart. Methods: In thirty adult sheep radiopaque markers were placed as opposing pairs on the S-L and C-C aspects of the mitral annulus (ANN) and the basal, equatorial and apical level of the LV (LV1, LV2 and LV3, respectively, Fig, A). Ten true-sized Carpentier-Edwards Physio 1 (PHY), Edwards IMR ETLogix (ETL), and GeoForm (GEO) annuloplasty rings were inserted in a releasable fashion. Under acute open chest conditions 4-D marker coordinates were obtained using biplane videofluoroscopy with ring inserted at bas...