title: Higher energy synchronized external direct current cardioversion for refractory atrial fibrillation.
abstract: OBJECTIVE
  We sought to evaluate the safety and efficacy of higher energy synchronized cardioversion in patients with atrial fibrillation refractory to standard energy direct current (DC) cardioversion.
  
  
  BACKGROUND
  Standard external electrical cardioversion fails to restore sinus rhythm in 5% to 30% of patients with atrial fibrillation.
  
  
  METHODS
  Patients with atrial fibrillation who failed to achieve sinus rhythm after at least two attempts at standard external cardioversion with 360 J were included in the study. Two external defibrillators, each connected to its own pair of R-2 patches in the anteroposterior position, were used to deliver a synchronized total of 720 J.
  
  
  RESULTS
  Fifty-five patients underwent cardioversion with 720 J. Mean weight was 117 +/- 23 kg (body mass index 48.3 +/- 4.1 kg/m2). Structural heart disease was present in 76% of patients. Mean left ventricular ejection fraction was 45 +/- 12%. Atrial fibrillation was present for over three months in 55% of the patients. Sinus rhythm was achieved in 46 (84%) of the 55 patients. No major complications were observed. No patient developed hemodynamic compromise and no documented cerebrovascular accident occurred within one month after cardioversion. Of the 46 successful cardioversions, 18 patients (39%) remained in sinus rhythm over a mean follow-up of 2.1 months.
  
  
  CONCLUSIONS
  External higher energy cardioversion is effective in restoring sinus rhythm in patients with atrial fibrillation refractory to standard energy DC cardioversion. This method is safe and does not result in clinical evidence of myocardial impairment. It may be a useful alternative to internal cardioversion because it could be done within the same setting of the failed standard cardioversion and obviates the need to withhold protective anticoagulation for internal cardioversion.
authors.affiliation: Department of Cardiology, Section of Cardiac Electrophysiology and Pacing, The Cleveland Clinic Foundation, Ohio 44124, USA.
authors.forename: W
authors.initials: W
authors.lastname: Saliba
authors.forename: N
authors.initials: N
authors.lastname: Juratli
authors.forename: M K
authors.initials: MK
authors.lastname: Chung
authors.forename: M J
authors.initials: MJ
authors.lastname: Niebauer
authors.forename: O
authors.initials: O
authors.lastname: Erdogan
authors.forename: R
authors.initials: R
authors.lastname: Trohman
authors.forename: B L
authors.initials: BL
authors.lastname: Wilkoff
authors.forename: R
authors.initials: R
authors.lastname: Augostini
authors.forename: K A
authors.initials: KA
authors.lastname: Mowrey
authors.forename: G R
authors.initials: GR
authors.lastname: Nadzam
authors.forename: P J
authors.initials: PJ
authors.lastname: Tchou
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D004452:Echocardiography; D004554:Electric Countershock / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D015635:Radionuclide Ventriculography; D012008:Recurrence; D012189:Retrospective Studies; D013318:Stroke Volume; D016896:Treatment Outcome