Left Ventricular Remodeling in PVC-induced Cardiomyopathy: Effect of Coupling Intervals and AV Dissociation.

BackgroundLV dyssynchrony (LVD) and post extra systolic potentiation (PESP) associated with premature ventricular contractions (PVC) may play a role in the development of PVC-induced cardiomyopathy (PVC-CM). Long-coupled (LC) PVCs have greater LVD than short-coupled (SC) PVCs, while SC-PVCs stronger PESP LC-PVCs.ObjectiveCompare LC-PVCs to evaluate roles LVD, PESP, atrioventricular dissociation (AVD) PVC-CM.MethodsThirty-six canines underwent pacemaker implantation induce bigeminal right apical epicardial (50% burden) for 12 weeks. Telemetry assessed PVC burden AVD. Animals were grouped as SC-PVC (CI 200-220ms), LC-PVC 330ms), sham (control). Echocardiographic changes, AVD, hemodynamics monitored weeks.ResultsPVC was similar between groups, but statistically higher group vs. 47.5%, p=0.028). After weeks, left ejection fraction (LVEF) significantly decreased both groups (47.1±1.4% 45.5±2%, respectively) compared (61 ± 1.6%, p<0.001). Overall, AVD there no significant correlation reduction LVEF at weeks (r=0.09, p=0.5; r=0.06, p=0.8, respectively). Additionally, experienced substantial declines max min dP/dt after baseline.ConclusionNeither coupling interval nor played an independent or severity PVC-CM. equal relative contributions