“serious complications continue to occur even in the most experienced hands… New, devastating complications are emerging. Perhaps the most frightening of these is esophageal perforation, which is often lethal — and atrioesophageal fistulas, which are perhaps the most feared and most lethal of the many complications that have been associated with this procedure – with mortality in excess of 75 percent… and new complications are being ‘discovered’ on a regular basis…” http://www.medicalnewstoday.com/medicalnews.php?newsid=50308
“there have been no large randomized multicenter clinical trials performed to determine the safety and efficacy of catheter ablation of AF” 2007. http://www.medscape.com/viewarticle/558137_3
Collateral Damage: A Patient, a New Procedure and the Learning Curve 