Key result
Short and long-coupled PVCs similarly reduce LVEF vs sham, showing coupling interval does not drive PVC-CM.
Why the study?
The roles of LV dyssynchrony, post extra systolic potentiation, and atrioventricular dissociation in the development of premature ventricular contraction-induced cardiomyopathy remained unclear.
Does the PVC coupling interval or atrioventricular dissociation affect the development of PVC-induced cardiomyopathy in a canine model?
Does the PVC coupling interval or atrioventricular dissociation affect the development of PVC-induced cardiomyopathy in a canine model?
In a canine model, neither PVC coupling interval nor atrioventricular dissociation independently determined the severity of PVC-induced cardiomyopathy, suggesting left ventricular dyssynchrony and post-extrasystolic potentiation contribute equally.
Does not support altering PVC management by coupling interval; leaves open mechanistic roles of dyssynchrony and potentiation in human PVC-CM.
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 a greater LVD than short-coupled (SC) PVCs, while SC-PVCs have a stronger PESP than LC-PVCs.ObjectiveCompare SC-PVCs and LC-PVCs to evaluate the roles of LVD, PESP, and atrioventricular dissociation (AVD) in the development of PVC-CM.MethodsThirty-six canines underwent pacemaker implantation to induce bigeminal right ventricular apical epicardial PVCs (50% burden) for 12 weeks. Telemetry assessed PVC burden and AVD. Animals were grouped as SC-PVC (CI 200-220ms), LC-PVC (CI 330ms), and sham (control). Echocardiographic changes, AVD, and hemodynamics were monitored for 12 weeks.ResultsPVC burden was similar between SC-PVC and LC-PVC groups, but statistically higher in the SC-PVC group (50% vs. 47.5%, p=0.028). After 12 weeks, left ventricular ejection fraction (LVEF) significantly decreased in both SC-PVC and LC-PVC groups (47.1±1.4% and 45.5±2%, respectively) compared to sham group (61 ± 1.6%, p<0.001). Overall, AVD was similar between SC-PVC and LC-PVC groups, and there was no significant correlation between AVD and the reduction in LVEF at 12 weeks (r=0.09, p=0.5; r=0.06, p=0.8, respectively). Additionally, both SC-PVC and LC-PVC groups experienced substantial declines in max and min dP/dt after 12 weeks compared to baseline.ConclusionNeither the PVC coupling interval nor AVD played an independent role in the development or severity of PVC-CM. LVD and PESP have equal relative contributions to the development of PVC-CM.
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Shoureshi et al. (2023) studied PVC-induced cardiomyopathy (n=36). Short-coupled (SC) and Long-coupled (LC) PVCs vs. Sham (control) was evaluated on Left ventricular ejection fraction (LVEF) at 12 weeks (p=<0.001). Short-coupled and long-coupled PVCs similarly decreased LVEF after 12 weeks compared to sham (47.1% and 45.5% vs 61%, p<0.001), indicating coupling interval does not independently drive PVC-CM.
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