title: Low energy internal atrial cardioversion in atrial fibrillation lasting more than a year.
abstract: The aim of this study was to evaluate the efficacy of low energy internal atrial cardioversion in restoring sinus rhythm (SR) in patients with chronic atrial fibrillation (AF) persisting > 1 year. Fifteen patients with chronic AF lasting > 1 year (from 13-48 months, mean 24 +/- 13 months) were studied. R wave synchronized 3/3 ms biphasic shocks were delivered between right atrial and coronary sinus (left pulmonary artery in five patients) electrodes. Sedatives or anesthetics were administered only at the patient's request.
  
  
  RESULTS
  Stable SR was restored in 14 (93%) of 15 patients after shocks with a mean leading edge voltage of 377 +/- 77 V (range 260-500) and a mean delivered energy of 7.3 +/- 3.4 J (range 2.6-12.9). The procedure was performed without anesthesia in 6 (40%) patients. All successfully cardioverted patients were treated with flecainide, sotalol, or amiodarone. During a follow up of 7.7 +/- 7.9 months (range 1-24) AF recurred in five (36%) patients. Three of five AF recurrences occurred within 3 days after conversion to SR.
  
  
  CONCLUSIONS
  Internal low energy atrial cardioversion is highly effective in restoring SR even in patients with AF lasting > 1 year. The long-term results from the standpoint of freedom from AF recurrences, are satisfactory, although additional antiarrhythmic treatment is required, particularly in the first days after conversion.
authors.affiliation: Institute of Cardiology, University of Bologna, Italy. cardio1@almadns.unibo.it
authors.forename: G
authors.initials: G
authors.lastname: Boriani
authors.forename: M
authors.initials: M
authors.lastname: Biffi
authors.forename: F
authors.initials: F
authors.lastname: Pergolini
authors.forename: R
authors.initials: R
authors.lastname: Zannoli
authors.forename: A
authors.initials: A
authors.lastname: Branzi
authors.forename: B
authors.initials: B
authors.lastname: Magnani
mesh_terms: D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000628:therapy*; D006328:Cardiac Catheterization; D002908:Chronic Disease; D004554:Electric Countershock / Q000379:methods*; D017097:Electric Impedance; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery; D055502:Secondary Prevention; D016896:Treatment Outcome