A 62-year-old woman had a history of catheter ablation three times in the past for atrial fibrillation underwent the fourth catheter ablation. Atrial septum was punctured by Brockenbrough procedure. Two 8 Fr sheaths were inserted into left atrium. But blood was not drawn from the sheaths, and right atrial imaging confirmed that sheaths penetrated into cardiac sac. Pericardial fluid gradually increased and state of shock was seen due to cardiac tamponade. Drainage was performed through sheaths and hemodynamic condition was stabilized. It was judged that urgent surgical repair was necessary. When cardiopulmonary bypass was attached and right atrial incision was made under cardiac arrest, two sheaths were piercing from right atrial to pericardial transverse sinus on the dorsal side of ascending aorta. After removing the sheaths, the perforation was closed directly inside and outside right atrial wall. The postoperative course was generally good.