Complex Fractionated Atrial Electrograms, Dispersion, and Voltage in Persistent Atrial Fibrillation: Implications for...

Area of Science:

• Electrophysiology
• Cardiac Arrhythmias
• Medical Device Technology

Background:

• Identifying the substrate of persistent atrial fibrillation (PeAF) is crucial for effective treatment.
• Current methods include complex fractionated atrial electrograms (CFAEs), electrogram dispersion, and low-voltage areas (LVAs).
• The relationship between these markers and their changes after catheter ablation requires further investigation.

Purpose of the Study:

• To investigate the relationship between CFAEs, electrogram dispersion, and low-voltage areas in PeAF patients.
• To analyze how these electrophysiological markers change following catheter ablation (pulmonary vein and posterior wall isolation - PVI+PWI).
• To explore the potential of these changes as predictors of treatment response.

Main Methods:

• Prospective recruitment of PeAF patients undergoing catheter ablation.
• High-density left atrial mapping before and after PVI+PWI (if AF persisted).
• Automatic annotation of dispersion tags using an AI system; analysis of CFAE regions and voltage characteristics.

Main Results:

• Dispersion tags were predominantly located within CFAE regions, which mostly had normal voltage (>0.5 mV).
• Post-ablation mapping showed reduced CFAE and dispersion, prolonged atrial cycle length, and CFAE de-escalation, even in non-ablation target areas.
• Patients with complete CFAE de-escalation across all regions had significantly lower recurrence rates (11.1%) compared to those without (53.3%).

Conclusions:

• Electrogram dispersion is associated with CFAEs and primarily reflects normal voltage areas.
• Ablation can lead to regional reductions in CFAE and dispersion burden outside directly targeted zones.
• Post-procedural de-escalation of electrograms may indicate response to PVI+PWI, warranting further research.