Left ventricular remodeling in premature ventricular contraction-induced cardiomyopathy: Effect of coupling intervals and atrioventricular dissociation.

Background: Left ventricular dyssynchrony (LVD) and postextrasystolic potentiation (PESP) associated with premature ventricular contractions (PVCs) may play a role in the development of premature ventricular contraction-induced cardiomyopathy (PVC-CM). Long-coupled (LC) PVCs have a greater LVD than short-coupled (SC) PVCs, whereas SC-PVCs have a stronger PESP than LC-PVCs.

Objective: The purpose of this study was to compare SC-PVCs and LC-PVCs to evaluate the roles of LVD, PESP, and atrioventricular dissociation (AVD) in the development of PVC-CM.

Hemodynamic response and safety of vasodilator stress cardiovascular magnetic resonance in patients with permanent pacemakers or implantable cardioverter-defibrillators.

Introduction: Vasodilator stress cardiovascular magnetic resonance (CMR) is a powerful diagnostic modality, but data toward its use in patients with permanent pacemakers (PPMs) or implantable cardioverter-defibrillators (ICDs) is limited.

Methods And Results: Patients with ICDs (>1% pacing) or PPMs who underwent regadenoson single photon emission computed tomography (SPECT) and all patients with ICDs or PPMs who underwent stress CMR were retrospectively identified. SPECT tests were analyzed for hemodynamic responses and new pacing requirements; CMR studies were examined for safety, device characteristics and programming, hemodynamic responses, and image quality.

Eccentric hypertrophy in an animal model of mid- and long-term premature ventricular contraction-induced cardiomyopathy.

Background: Tachycardia and heart rate irregularity are proposed triggers of premature ventricular contraction-induced cardiomyopathy (PVC-cardiomyopathy). Bigeminal premature atrial and ventricular contractions (PACs and PVCs) increase heart rate and result in rhythm irregularities but differ in their effects on ventricular synchrony. Comparing chronic bigeminal PACs with PVCs would provide insights into mechanisms of PVC-cardiomyopathy.