Abstract
A 58-year-old man admitted for a cryoballoon ablation due to a history of symptomatic paroxysmal atrial fibrillation experienced pericardial effusion and cardiac tamponade intraoperatively. A longitudinal left superior pulmonary vein perforation was confirmed by emergency thoracotomy and repaired. He developed atrial fibrillation 2 days postoperatively, which was terminated with colchicine and oral steroids the following day.