Abstract 17038: Neural Remodeling and Increased Pro-arrhythmia in A Canine Model of Premature Ventricular Contraction-induced Cardiomyopathy
Introduction: Premature Ventricular Contraction (PVC)-Induced Cardiomyopathy (CM) is a major cause of non-ischemic CM. However, the presence or absence of neural remodeling and its consequences in PVC-induced CM are unknown.
Methods: In 6 normal canines, PVC-induced CM was induced by chronic bigeminal PVC application (200ms-CL) using a novel premature pacing algorithm. We implanted Data Sciences International devices to directly record left stellate ganglion nerve activity (SGNA), left cardiac vagal nerve activity (VNA) for 12 weeks. Ambulatory recordings were performed at baseline sinus rhythm at rest and during 9-min treadmill exercise testing (up to 3.3mph), and repeated after development of CM.
Results: PVC stimulus was disabled after 12-weeks with resultant development of CM in all animals. Compared with baseline (Table), PVC-induced CM was associated with significantly elevated resting SGNA (p=0.04). There was no significant change in resting VNA (p=0.17). Exercise-induced increases in SGNA (but not VNA) were noted at baseline (141±62 to 461±53 μV-s, p<0.01) and after CM (505±33 to 691±155 μV-s, p=0.03) vs rest, however, the response was blunted in CM (1.4 times exercise-induced augmentation in CM vs 3.3 times at baseline). There was a 3-fold prolongation of the baroreflex sympathetic efferent response time to acute PVC stimulus in CM compared to baseline, and an increased spontaneous paroxysmal atrial tachyarrhythmia, PVCs and ventricular tachycardia (p=0.015).
Conclusions: Neural remodeling is present in PVC-Induced CM and is characterized by increased sympathetic nerve activity at rest and exercise, without significant change in vagal nerve activity. The consequences include delayed baroreflex-mediated sympathetic response to PVCs, blunted sympathetic response to exercise and increased spontaneous atrial and ventricular arrhythmias.
Author Disclosures: A.Y. Tan: None. P. Mankad: None. R. Cardona-Guarache: None. M. Howren: None. M. Joslyn: None. S. Lin: None. K. Kaszala: None. A. Minisi: None. K. Ellenbogen: None. J. Huizar: None.
- © 2016 by American Heart Association, Inc.