Substrate modification by adding ablation of localized complex fractionated electrograms after stepwise linear...

Area of Science:

• Electrophysiology
• Cardiac Ablation
• Atrial Fibrillation

Background:

• Linear left atrial (LA) ablation effectively eliminates many complex fractionated electrogram (CFE) sites in patients with persistent atrial fibrillation (PsAF).
• However, residual CFE sites may persist after initial linear ablation, potentially impacting treatment success.

Purpose of the Study:

• To evaluate the impact of localized CFE ablation combined with standard linear LA ablation in PsAF patients.
• To determine if additional CFE-targeted ablation improves substrate modification and clinical outcomes.

Main Methods:

• Forty PsAF patients underwent electroanatomical mapping (NavX) to identify CFE and dominant frequency (DF) sites.
• A stepwise linear ablation strategy was performed, followed by additional ablation targeting localized CFE sites identified by an automatic algorithm.
• Mapping and ablation were guided by CFE characteristics and DF.

Main Results:

• Linear ablation significantly reduced the continuous CFE burden (69% to 21%).
• Localized CFEs (40-120 ms) were predominantly found in anterior, posterior, and inferior LA regions.
• Additional CFE-targeted ablation terminated PsAF in 20% of patients, increased CFE cycle length, and decreased DF in the coronary sinus.

Conclusions:

• Localized CFE sites identified after linear ablation represent optimal targets for selective substrate modification in PsAF.
• This combined ablation strategy enhances the effectiveness of atrial fibrillation treatment by addressing residual electrophysiological abnormalities.