Introduction:
Atrial septal defect is the most common congenital heart lesion in adults, and the surgical intervention of closure of the percutaneous atrial septal defect are increasing recently. Implantation of the atrial septal device may protect these patients from potential complications induced by ASD, but in a later stage can predispose them to other complications. AF is more common in patients with the occluder compared with the general population.1 Radiofrequency ablation is recommended for AF, especially for the drug-refractory symptomatic AF.2 Safe and easy access to the left atrium through the occlusion device is the basic and critical step for catheter ablation, which dissuades electrophysiologists from performing ablation in patients showing an alternation of septal anatomy or predisposed with a potential risk of complications. Here we describe the successful interventional strategy following a peripheral balloon created transseptal access for AF ablation in the setting of a large-sized septal occlusion device implantation.