Abstract 2744: Left Atrial Appendage: An Undercognized Trigger Site of Atrial Fibrillation
Introduction: The left atrial appendage (LAA) is an underestimated site of initiation of atrial fibrillation. We report the prevalence of trigger from the LAA and the best strategy for successful ablation.
Methods: 987 consecutive patients (76% chronic and 24% paroxysmal) undergoing redo catheter ablation for symptomatic and drug resistant atrial fibrillation have been enrolled in this study. Patients showing firing from LAA were identified and ablated. Ablation was performed either with focal lesion (21 patients) or to achieve LAA isolation guided by placement of the circular catheter at the ostium of the LAA (65 patients).
Results: 86 patients out of 987 (8.7%), 81 patients with chronic and 5 patients with paroxysmal AF, showed triggers initiating atrial arrhythmias from the LAA. In 21 patients focal lesions were delivered. In all other cases LAA isolation was performed. In 50% (43 pts) of these patients, isolation of the LAA required circumferential isolation. In the remaining patients segmental ablation was sufficient to achieve isolation. The mean RF time for the circumferential isolation was 41±6 minutes, while for the focal ablation it was 15±5 minutes. 3 pericardial effusion requiring pericardiocentis occurred. The success rate after the first procedure and second procedure at 6 months follow up is shown in the table⇓.
Conclusions: The success rate of focal ablation of the LAA is dismal. Isolation of the LAA may be necessary during catheter ablation of atrial fibrillation. After LAA isolation the reconnection rate is 46%. Similarly to the pulmonary veins, the LAAs can be isolated with segmental ablation in some patients.