Durable pulmonary vein isolation but not complex substrate ablation determines the type of arrhythmia recurrence after persistent atrial fibrillation ablation.

Background: Complex ablation for persistent atrial fibrillation (AF) aims to modify the arrhythmogenic substrates to become incapable to perpetuate the arrhythmia. Ablation-associated determinants of atrial tachycardia (AT) rather than AF recurrences are unknown. The aim of the study was to evaluate the association between the type of arrhythmia recurrence and electrophysiological findings during redo procedures.

Methods: A total number of 384 consecutive patients with persistent AF underwent complex ablation consisting of PV isolation (PVI), biatrial electrogram-guided ablation, and linear ablation with the desired procedural endpoint of AF termination. Electrophysiological findings during redo procedures and its relation to AR type are the subject of this study.

Results: Overall, 177 (46%) patients underwent a second procedure. Patients with AT recurrences had significantly more often persistent PVI (47 vs. 25%; P = 0.002). Moreover, a higher number of recovered PVs were associated with AF recurrence (3 PVs recovered, AF = 16.1% vs. AT = 5.2%; P = 0.02; 4 PVs recovered, AF = 18.5% vs. AT = 6.3%; P = 0.01), regardless of the extent of substrate ablation during the first procedure.

Conclusions: Durable PV isolation but not the extent of atrial substrate ablation determines the type of arrhythmia recurrence. Thus, the PVs may represent dominant perpetuators (and not only triggers) of persistent AF even in the presence of a significantly modified atrial substrate.