Abstract 13847: Post-Ablation Atrial Tachycardia: The Role of the Septum
Introduction: Ablation of AF can lead to the development of clinically challenging atrial tachycardias (AT). These ATs tend to localize to certain anatomical regions. Herein we examine the impact of AT isthmus location on acute and long-term outcomes of ablation utilizing an approach of sequential high-density activation and entrainment mapping.
Methods: 81 consecutive patients presenting with AT underwent high-density mapping using a multipolar catheter with an impedance-based mapping system. The approach consisted of 4 steps: 1) use of a high-density catheter to create an activation map during tachycardia; 2) analysis of the patterns of atrial activation to identify wavefronts of electric propagation; 3) targeted entrainment of putative channels; and 4) irrigated radiofrequency ablation of constrained regions of the circuit. Follow-up consisted of clinic visits and event monitoring.
Results: Of the 81 patients, 55 (68%) were s/p catheter ablation for AF, 8 (10%) s/p MAZE and 18 (22%) had underlying structural heart disease involving the atria. A total of 154 ATs (mean: 1.9 AT/ pt) were identified and targeted. 42 (27%) ATs were of septal origin. Successful ablation was achieved in 136 (88%) ATs; all ATs were eliminated in 72 (94%) pts. Both acute and chronic failures occurred disproportionately in septal ATs. The acute success rate was 93% for non-septal ATs and 76% for septal ATs (P=0.004). During a mean follow-up period of 19 ± 12 months, 78% of pts remained free of AT. For pts with one or more septal AT, the chronic success rate was 66%, while for patients with no septal ATs, the chronic success rate was 84% (P<0.05).
Conclusions: High-density activation mapping combined with entrainment mapping offers an efficient and reliable approach to treatment of post-ablation AT. However, the presence of septal AT limits the effectiveness of this approach, both acutely and chronically. New tools or approaches for the ablation of septal ATs are needed.
- © 2011 by American Heart Association, Inc.