Left Ventricular Dyssynchrony Predicts the Cardiomyopathy Associated With Premature Ventricular Contractions
Key result
LV epicardial PVCs induce cardiomyopathy in swine, dropping LVEF to ~40%.
- P<0.01
- n=35
Why the study?
The pathophysiology of cardiomyopathy associated with premature ventricular contractions remains unclear.
Does the site of paced ectopic beats and resulting LV dyssynchrony predict the severity of PVC-induced cardiomyopathy in a swine model?
Key Points
- To determine whether mechanical left ventricular dyssynchrony serves as an independent predictor for the development of cardiomyopathy associated with frequent premature ventricular contractions.
- Evaluated left ventricular mechanical synchrony and cardiac function in individuals presenting with premature ventricular contractions.
- Assessed the association between dyssynchrony parameters and the onset or severity of ventricular dysfunction.
- Left ventricular dyssynchrony strongly correlates with the presence and progression of cardiomyopathy induced by premature ventricular contractions.
- Mechanical discoordination serves as a reliable marker to identify individuals at elevated risk of developing ventricular contractile impairment.
Structured PICO
Does the site of paced ectopic beats and resulting LV dyssynchrony predict the severity of PVC-induced cardiomyopathy in a swine model?
P
Population
35 swine undergoing pacemaker implantation exposed to various pacing protocols for 12-14 weeks to study PVC-induced cardiomyopathy.
I
Intervention
Paced bigeminy from the right ventricular apex (RVA) for 14 weeks, right ventricular free wall (RVFW) for 12 weeks, left ventricular epicardium (LV Epi) for 12 weeks, or right atrium (premature atrial complex) for 12 weeks
C
Comparator
Regular pacing from the RVA at 140 beats/min (RV-140) and an unpaced control group
O
Outcome
Left ventricular ejection fraction (LVEF) and ventricular fibrosissurrogate
Main Result
p-value: p=<0.01
In a swine model, PVC-induced cardiomyopathy severity is strongly associated with the extent of LV dyssynchrony, demonstrating a distinct phenotype from tachycardia-induced cardiomyopathy.
Authors
Discussion
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Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
JMJonathan MossAssociate Professor of Clinical Medicine, UCSF
“This study revealed numerous important findings. In a swine model, cardiomyopathy induced with paced ectopic beats is phenotypically different from that induced with paced ventricular tachycardia, specifically regarding changes in cellular proteins associated with calcium handling. Additionally, the severity of the induced cardiomyopathy was strongly associated with the degree of ventricular dyssynchrony during ectopic beats, as demonstrated by comparing animals with ectopic beats delivered from different ventricular sites.”
“Several retrospective studies have sought to identify differences in the characteristics of PVCs among patients with versus without reversible cardiomyopathy. The most consistent factor associated with reversible cardiomyopathy was PVC burden.”
Implication
May aid PVC risk stratification; leaves open prospective trials before practice change.
Cite This Study
Walters et al. (2018) studied Cardiomyopathy associated with premature ventricular contractions (n=35). Paced ectopic beats (PVCs) vs. Regular pacing at 140 beats/min and no pacing (control) was evaluated on Left ventricular ejection fraction (LVEF) (p=<0.01). In a swine model, paced ectopic beats induced cardiomyopathy, with left ventricular epicardial PVCs causing a significant decline in LVEF from 65.2% to 39.7% (p<0.01).