Refractory atrial tachycardia after transcatheter closure of an atrial septal defect, successfully treated by catheter ablation with transseptal approach via the side of the device.

Atrial tachyarrhythmias occurring after transcatheter atrial septal defect closure are not uncommon; however, those related to device stimulation are rare. Herein, a case involving a 24-year-old female, who developed drug-refractory atrial tachycardia during the early postoperative period, is reported. The results of electroanatomical mapping could eventually be obtained from both atria. They revealed a focal pattern, and the earliest site was located on the left atrial side of the superior atrial septum, between the left and right atrial discs of the device. An ablation catheter was inserted through the side of the device into the left atrial septum, and cauterization successfully achieved recovery of the sinus rhythm without device dislodgement. Learning objective: Atrial tachyarrhythmia related to mechanical stimulation with an atrial septal defect closure device in the early perioperative period is a rare complication. Catheter ablation with transseptal approach through the side of the device might be an option, although careful attention should be paid to the risk for device dislodgement.