96-17: Atrial tachycardias in patients with long-standing persistent atrial fibrillation undergoing thoracoscopic epicardial RF ablation

Abstract

Introduction: Surgical epicardial thoracoscopic RF ablation (SETA) was shown to be more effective in terms of clinical results than catheter based procedures in patients with atrial fibrillation (AF). However, neither surgery nor catheter ablation alone can achieve 100% complete and durable transmural lesions. The aim of this study was to determine mechanisms and localization of atrial tachycardias found after epicardial ablation. Methods: Patients with long-standing persistent AF underwent SETA with aim to create circumferential lesions around the ipsilateral pulmonary veins (PVs) using bipolar RF clamps, to complete linear connecting lesions and to ablate ganglionated plexi using linear pen. As a second step, a detailed 3D electroanatomical mapping (EAM) of both atria using CARTO3 system was performed within 6-8 weeks following surgical procedure. All spontaneous or induced atrial tachycardias (ATs) were mapped and ablated. Results: Sixty patients (mean age 62 years, LA diameter 49 ± 6 mm) were studied. Forty-five patients (75%) had sinus rhythm in the beginning of EAM. Six patients (10%) had typical CTI-dependent right atrial flutter; two patients (5.1%) had right atrial (RA) tachycardia, one patient (2.6%) had focal tachycardia arising from the middle CS, three patients (5%) had perimitral left atrial (LA) flutter, and finally, four patients (6.7%) had AF. All spontaneous ATs were successfully mapped and ablated. As a part of protocol, incremental atrial pacing was performed after finalization of all lines and PV isolations at the end of procedure. In 46 patients (76.7%), no sustained AF and/or AT was induced, in three patients (5%), AF lasting > 30 s was induced, but spontaneously terminated. Non self-terminating AF was induced in two patients (3.3%). In the remaining 9 patients (15%), 13 ATs were induced: 6 arising from the RA and 7 arising from the LA. All but 2 ATs were successfully abolished by RF ablation. Mean procedure and fluoroscopic times of the whole procedure reached 132 ± 37 min and 8 ± 2 min, respectively. 84% of patients maintained stable SR off antiarrhythmic therapy at 12-month follow-up. Reasonable arrhythmia control was achieved in 94% of patients. Conclusion: At least one quarter of patients are suffering from spontaneous ATs and/or AF after SETA. Catheter ablation of ATs following surgery is safe and highly effective. Sequential hybrid approach seems to achieve normal SR in vast majority of patients with previously long-standing persistent AF.