Response of secondary mitral regurgitation to cardiac resynchronization therapy: is the atrium to blame?

Secondary mitral regurgitation (MR) is common in patients eligible for cardiac resynchronization therapy (CRT). The prevalence is estimated between 15% in NYHA functional class I-II patients and 40% in NYHA class III-IV patients.1 The mechanisms underlying secondary MR in this population are multifactorial. Left ventricular (LV) and mitral annulus dilatation due to ischemic or non-ischemic cardiomyopathy impair leaflet coaptation of a structurally normal mitral valve resulting in functional MR. More specifically in CRT candidates, mechanical dyssynchrony, together with LV dysfunction contributes to apical and lateral papillary muscle displacement, resulting in leaflet tethering and reduced valve closing forces.

Source: Heart Rhythm - July 28, 2018 Category: Cardiology Authors: Vincent Galand, Raphael P. Martins, Claude Daubert Source Type: research