Left Ventricular Dyssynchrony Predicts the Cardiomyopathy Associated With Premature Ventricular Contractions

Abstract Background The pathophysiology of cardiomyopathy associated with premature ventricular contractions (PVCs) remains unclear. Objectives This study prospectively explored cardiomyopathy development in a swine model of paced ectopic beats. Methods A total of 35 swine underwent pacemaker implantation. A group exposed to paced bigeminy from the right ventricular apex (RVA) for 14 weeks (RVA PVC) (n = 10) were compared with a group exposed to regular pacing from the RVA at 140 beats/min (RV-140) (n = 5) and a control group (n = 5). To test the role of ectopic beat dyssynchrony, further groups were exposed for 12 weeks to bigeminy from the right ventricular free wall (RVFW PVC) (n = 5), the left ventricular epicardium (LV Epi PVC) (n = 5) or the right atrium (premature atrial complex) (n = 5). Results After 14 weeks, the mean left ventricular ejection fraction (LVEF) was significantly lower in the RVA PVC group than in the RV-140 or control groups (p  Conclusions In a swine model of paced ectopic beats, PVC-induced cardiomyopathy is phenotypically distinct from a tachycardia-induced cardiomyopathy. Cardiomyopathy severity is strongly associated with severity of the hemodynamic derangement associated with the paced ectopic beats, particularly the extent of LV dyssynchrony.