Related Experiment Video
Updated: Aug 10, 2026
09:17
High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation
Published on: July 29, 2011
Atrial Fibrillation Initiation Arises From Reentry at Patient-Specific Regions With Steep Repolarization Gradients
Elad Anter1, Michael Barkagan1, Dor Yadin1
1Cardiac Electrophysiology Section, Division of Cardiovascular Medicine, Shamir Medical Center, Be'er Yaakov, Israel; Gray Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel.
JACC. Clinical Electrophysiology
|August 8, 2026
Summary
Atrial fibrillation (AF) initiation stems from localized, patient-specific sites supporting re-entry. Identifying these sites with programmed stimulation enables individualized ablation strategies for better outcomes.
Area of Science:
- Electrophysiology
- Cardiology
- Medical Devices
Background:
- The precise mechanism initiating atrial fibrillation (AF) via ectopic beats is not fully understood.
- Identifying the underlying substrate for AF initiation is crucial for effective treatment.
Purpose of the Study:
- To define the mechanism and substrate responsible for initiating atrial fibrillation (AF).
- To investigate the role of steep repolarization gradients (SRGs) in AF initiation.
- To evaluate the efficacy of substrate-guided ablation for AF.
Main Methods:
- Biatrial mapping and programmed extrastimulation were used in 57 AF patients and 24 controls.
- Electrophysiological parameters were assessed at AF initiation sites.
- Ablation was performed on identified substrate sites in a subset of patients.
Main Results:
- AF initiation was localized to discrete, patient-specific sites (2.8% of tested locations).
- Steep repolarization gradients (SRGs) were strongly associated with AF initiation (91.7% of AF patients vs 8.3% controls).
- Substrate-guided ablation in redo patients achieved 87.5% freedom from atrial arrhythmia.
Conclusions:
- Atrial fibrillation initiation originates from a localized substrate supporting re-entry, identifiable via programmed stimulation.
- These findings support a shift towards individualized, substrate-guided ablation for AF treatment.
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