Epicardial ablation of refractory focal atrial tachycardia after a failed endocardial approach.

Background: Endocardial ablation is effective for most focal atrial tachycardias (FATs). In rare circumstances, the FAT can originate from the epicardial side of the atrium.

Objective: In the present study, we retrospectively assessed the percutaneous approach for epicardial ablation of FAT when standard endocardial ablation had failed.

Methods: Among a consecutive 186 patients undergoing ablation for 198 FATs, epicardial mapping and ablation via a percutaneous subxiphoid approach were attempted in 10 patients because of failed endocardial ablation.

Results: In 3 cases, the origin of FAT was at the epicardial side of the junction of the right atrial appendage and superior vena cava. In 3 cases, the origin of FAT was located in the epicardial region of the left atrial insertion of Bachmann bundle. In 2 cases, the FAT originated from the epicardial side of the right atrial free wall. In 1 case, the FAT was successfully ablated from the epicardial side of the right atrial appendage, and in the remaining case, the origin of FAT was located in the epicardial region of the vein of Marshall. All FATs were successfully eliminated by ablation at the epicardial earliest activation site.

Conclusion: Epicardial mapping and ablation can be considered as an effective and safe option for FAT resistant to endocardial ablation.