Authors: Estelle Renard, Michel Haïssaguerre, Laura R Bear, Olivier Bernus

Published in: Heart Rhythm, Volume 22, Issue 5, Pages 1345-1354 (May 2025)

Publication Date: Published online October 21, 2024

Abstract

Background: Repolarization variations contribute to ventricular fibrillation (VF) initiation.

Objective: To examine how repolarization heterogeneity leads to VF triggers.

Methods: Using isolated porcine hearts with localized repolarization heterogeneity induced by pinacidil, researchers performed optical mapping and electrocardiography.

Results: The study showed 74 VF episodes in 13 hearts (82%), triggered by premature ventricular complexes with brief coupling intervals (297 ± 66 ms). All 16 optically mapped VF initiations originated from border zones between altered and normal repolarization areas, where action potential duration and repolarization time gradients were significantly steeper.

Conclusion: Findings indicate VF triggers consistently emerge from repolarization dispersion boundaries, suggesting phase 2 reexcitation mechanisms.

Links:
• PubMed: https://pubmed.ncbi.nlm.nih.gov/39442641/
• DOI: 10.1016/j.hrthm.2024.10.027
• PMCID: PMC12048301