Comparative evaluation of symmetric and asymmetric ischemic mitral regurgitation according to the three-dimensional transesophageal and two-dimensional transthoracic echocardiography

Abstract

The development and progression of chronic ischemic mitral regurgitation (IMR) is associated with mitral tethering phenotype determined by localization of myocardial infarction (MI).
Purpose. To evaluate three-dimensional (3D) mitral valve (MV) parameters in symmetric and asymmetric mitral regurgitation (MR) and analyze correlations with MR severity, left ventricle (LV) global and local remodeling.
Methods. 43 patients with chronic IMR underwent 3D transesophageal and two-dimensional (2D) transthoracic echocardiography. Occlusion of one or more coronary arteries was diagnosed in 100% (n=43) of patients.
Results. In asymmetric IMR, caused by inferoposterior MI tenting area significantly increases, tenting volume is also enlarged, but less in size than in symmetric type. In asymmetric MR 3D MV geometry changes are affected by local LV remodeling (i.e. apical displacement of posteromedial papillary muscles [ADPM PM]) that causes restriction of MV posterior leaflet. Posterolateral angle in asymmetric pattern is explicitly associated with ADPM PM and IMR severity. This fact reflects predominantly systolic restriction of posterior leaflet on one hand and on the other indicates involvement of MV dysfunction mechanism in MR progression. In symmetric IMR MV geometry changes in greater degree than in asymmetric one depend on LV dilatation and ejection fraction reduction. Comparative analysis shows significant differences of 3D MV parameters in two MR phenotypes.
Conclusions. 3D MV geometric and functional alterations, global/local LV remodeling and regurgitation severity significantly differ in symmetric and asymmetric MR. 3D MV geometry and function changes are associated with MR phenotype determined by MI localisation.