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 < 0.05). LVEF declined significantly in the LV Epi PVC (65.2 ± 2.4% to 39.7 ± 3.0%; p < 0.01) and RVFW PVC (66.1 ± 2.6% to 48.6 ± 2.7%; p < 0.01) groups, with final LVEF significantly lower and ventricular fibrosis significantly higher in the LV Epi PVC group compared with all others (p < 0.05). Protein levels of pRyR2, NCX-1, CaMKII-α, and PLN were up-regulated and levels of SERCA2a were down-regulated in the LV Epi PVC group compared with the control group (p < 0.05). Longer ectopic beat QRS duration and greater LV dyssynchrony were significantly associated with larger declines in LV systolic function.

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.

• Authors: Tomos E Walters, Dolkun Rahmutula, Judit Szilagyi, Christina Alhede, Richard Sievers, Qizhi Fang, Jeffrey Olgin, Edward P Gerstenfeld
• Journal: Journal of the American College of Cardiology (J Am Coll Cardiol) Vol. 72 Issue 23 Pt A Pg. 2870-2882 (12 11 2018) ISSN: 1558-3597 [Electronic] United States
• PMID: 30522650 (Publication Type: Journal Article)
• Copyright: Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Topics

• Animals
• Cardiomyopathies (diagnosis, physiopathology)
• Predictive Value of Tests
• Swine
• Swine, Miniature
• Ventricular Dysfunction, Left (diagnosis, physiopathology)
• Ventricular Premature Complexes (diagnosis, physiopathology)