Ablation of Epicardial Posteroseptal Accessory Pathway With Anomalous Coronary Sinus Drainage Into Left Atrium

Catheter ablation of epicardial accessory pathways (APs) remains challenging, especially in patients with anatomical variations to the coronary sinus (CS).

We report a redo ablation case: A patient with an anomalous CS drainage into the left atrium, diagnosed with epicardial AP-mediated tachycardia, underwent successful ablation at the epicardial basal crux after failed previous endocardial ablation at the bilateral posterior septum.

This case demonstrates that ablation at the epicardial basal crux is safe and effective for epicardial APs associated with CS anatomical variations.

For treating tachycardia mediated by epicardial APs in patients with anomalous CS drainage into the left atrium, meticulous mapping and ablation targeting AP potential in the epicardial posteroseptal region may be safe and effective.