CARDIOVERSION OF ATRIAL-FIBRILLATION - RE SULTS AND COMPLICATIONS IN 1152 PROSPECTIVELY REGISTERED PATIENTS

Background: Pharmacological and direct-current cardioversion of atrial fibrillation are often performed interventions. Little is known about results and complications of cardioversion in daily practise. Patient s and methods: Demographic, procedural and outcome data from patients with cardioversion of atrial fibrillation were collected in a prospect ive, multicenter registry of 61 hospitals. Results: Between July 1994 and December 1994 1152 patients with a mean age of 64 +/- 11 years wer e registered on an intention-to-treat basis, 62% were male. The most p revalent underlying disorders were coronary artery disease (34.7%), va lvular heart disease (18.1%), and cardiomyopathy (6.9%). 16.4% of pati ents had lone atrial fibrillation. New onset atrial fibrillation was r eported in 21%, paroxysmal in 32% and chronic in 47% of patients. The mean duration of atrial fibrillation was 7 +/- 26 weeks (range 1 day t o 7 years, median 5 days). In 3.8% of patients no cardioversion attemp t was made and follow-up was not possible in another 5.5%. 19.2% of pa tients cardioverted spontaneously. Direct current cardioversion was at tempted in 39.7% and pharmacological cardioversion in 31.8% of patient s. Cardioversion was successful (sinus rhythm at discharge) in 96.4% o f spontaneous cardioversion, in 73.1% of direct current cardioversion and in 84.4% of pharmacological cardioversion. Success of cardioversio n was significantly related to duration of atrial fibrillation, NYHA f unctional class and left atrial diameter (p < 0.001). In 55 (4.8%) cas es complications were reported of which 14 were fatal. Five cases of s udden death occured, all of which were related to quinidine therapy fo r pharmacological cardioversion. Five cases of embolism were reported. Two were not associated with cardioversion attempts and 3 occured wit hin 24 hours after successful direct current cardioversion. Two of the se patients were effectively anticoagulated at the time of cardioversi on. A total of only 62% of patients with atrial fibrillation of more t han 48 hours duration were anticoagulated for cardioversion with couma dine or i.v. heparin. Conclusions: The main risks of cardioversion are fatal proarrhythmic events in pharmacological attempts to restore sin us rhythm. The risk of embolism is despite low rates of effective anti coagulation low.