Background: AF is a heterogeneous arrhythmia. At its simplest, it is triggered by rapidly firing foci around pulmonary veins (PV) and can be cured by isolation of PV alone. Evidences suggest that when high frequency of atrial activation is maintained for relatively longer period (as in persistent or long-standing AF), ion channel remodeling changes the electrophysiologic substrate and lead to AF permanence. Therefore, PVAI alone, as anticipated, demonstrates to have limited success rate in persistent and LSP AF and additional ablations beyond PVAI involving substrate modification are advocated by many experts in electrophysiology. However, there is yet no consensus on the ablation strategy for long-standing AF. It is still not clear whether AF termination during ablation could be considered as an ablation endpoint or not, as earlier studies have reported results that are at variance with each other. Some studies have suggested that termination of AF during ablation is associated with reduced recurrence of arrhythmia while others detected no association of AF termination with long-term maintenance of sinus rhythm (SR) in persistent or LSP-AF.Therefore this study aims to examine ablation outcomes in LSP-AF patients with AF termination with or without additional ablation of extra-PV triggers.
Hypothesis: AF termination does not eliminate the need for additional ablations in achieving long-term ablation success in LSP-AF.
