Abstract 16448: A Novel Mechanism of Atrial Fibrillation Persistence: Trigger-Based Mechanism and its Impact on the Efficacy of Catheter Ablation
Background: The mechanism of persistence of atrial fibrillation (AF) is still not fully understood. We investigated the possibility that frequent trigger action might play some roles in the development of persistent AF as well as presence of substrate.
Method: We enrolled 263 consecutive patients who underwent catheter ablation (CA) to persistent/permanent AF (peAF), and performed cardioversion at the beginning of CA procedure. We defined immediate recurrence of AF (IRAF) as AF recurrence within 90 seconds after restoration of sinus rhythm (SR) by cardioversion, and investigated the relation between IRAF and recurrence of AF.
Result: We performed average 1.3±0.5 session of CA, and IRAF was observed in 69 patients (26%). There were no difference between patients with and without IRAF in left atrial maximum volume (91±28 vs. 93 ±36 ml) and in the period of AF persistence before CA (27.6±37.3 vs. 26.3±33.3 months). We followed the study patients for 18±11 months, and those showing IRAF kept SR less frequently than those without IRAF (78.2% vs. 94.8 %, p<0.001). SR was kept in 48 out of 54 (89%) patients whose triggering PACs for IRAF were eliminated by CA though intensive substrate modification was performed only 24 patients (44.4%). Trigger PACs which initiate IRAF were unsuccessfully ablated in 15 out of 69 patients with IRAF(22%), and only five of them (33%) kept SR even though intensive substrate modification were performed except one (93%). The failure of elimination of PACs initiating IRAF was significantly related with recurrence of AF (relative risk = 6.0, 95% confident interval, 2.6 to 13.8)
Conclusion: Among patients with PeAF, the efficacy of CA was relatively low in patients with IRAF. Prevention of recurrent AF in these patients depended on the elimination of PAC initiating IRAF more than intensive substrate modifications. These results implied that the trigger could play a major role in AF persistence in some of patients with PeAF.
- © 2010 by American Heart Association, Inc.