Successful ablation of a right concealed epicardial accessory pathway using ethanol infusion

Introduction: This study describes a rare case of concealed epicardial accessory pathway (AP) successfully ablated using ethanol infusion (EI) through a variant vessel connecting the right atrium (RA) and the right ventricle (RV) surface.Methods and Results: A 58-year-old male referred to our hospital for prior failed AP ablation. Cardiac-enhanced computerized tomography scan showed there was a variant vessel at the tip of right atrial appendage and a pulmonary artery (PA)-RA fistula at the roof of RA. The earliest activation was present at the site of the PA-RA fistula. A selective angiography showed that a small branch of the variant vessel covered the earliest excitation site of the AP. EI into this branch successfully repressed the AP without any recurrences within a follow-up period of 3 months.Conclusion: Endocardial ablation is challenging for epicardial APs related to cardiac structural variations. If small vascular branches near the earliest activation site can be found, EI can successfully ablate these types of epicardial APs.