The most common complications reported are vascular injuries, pericardial tamponade, and cerebral thromboembolic events. Cappato and colleagues’ 2003–2006 survey of 85 centers that performed over 20,000 catheter ablations revealed a 4.5% rate of major complications, including cardiac tamponade, cerebral thromboembolic events, pulmonary vein stenosis, phrenic nerve injury, and, very rarely, atrioesophageal fistula. This is a decrease from a complication rate of 6% in an earlier Cappato and colleagues survey (1995–2002), in which data were gathered from 100 centers on 11,762 catheter ablations performed in 9,379 patients.Recent improvements in image mapping systems, irrigated-tip catheters, and periprocedural anticoagulation strategies have improved patient outcomes.