Both Electrical Isolation and Lesion Homogeneity Should be Focused: Evidence From Repeat Atrial Fibrillation Ablation.

BACKGROUND

Recurrent atrial tachyarrhythmia (AT) remains a major challenge following catheter ablation for atrial fibrillation (AF). While pulmonary vein (PV) reconnection is a well-recognized mechanism, the contribution of lesion heterogeneity to iatrogenic AT is not clearly defined.

OBJECTIVE

To analyze the clinical characteristics of recurrent AT caused by ablation-induced focal potentials.

METHODS

We retrospectively analyzed 113 patients who underwent repeat ablation for recurrent AT. Mechanisms of AT recurrence were identified using high-resolution electroanatomic mapping and categorized into five types. Nonuniform ablation-related AT-considered iatrogenic-was defined as focal or localized reentrant ATs arising from regions of prior ablation.

RESULTS

Gap conduction was the most common mechanism of recurrence (51.3%), followed by other mechanisms (27.4%) and nonuniform ablation-related AT (14.2%). The number of reconnected PVs was not significantly associated with the timing of all-mechanism recurrence. Nonuniform ablation-related ATs frequently presented as a combination of AF and atrial flutter (AFL), whereas gap-related recurrence typically manifested as AF.

CONCLUSION

Lesion homogeneity plays a critical role in minimizing iatrogenic ATs, highlighting the importance of ablation strategies that optimize both electrical isolation and lesion quality. These findings offer insights for the refinement of ablation techniques and the development of improved catheter technologies.