April 22, 2026
View Full PaperHigher energy synchronized external direct current cardioversion for refractory atrial fibrillation
Key Result
Higher energy synchronized external cardioversion (720 J) successfully restored sinus rhythm in 84% of patients with atrial fibrillation refractory to standard 360 J cardioversion.
Key Points
- To evaluate the safety and efficacy of higher energy synchronized cardioversion in patients with atrial fibrillation refractory to standard energy cardioversion.
- Included patients with atrial fibrillation resistant to standard cardioversion attempts using 360 J energy.
- Used two external defibrillators delivering a total of 720 J synchronized cardioversion.
- Assessed sinus rhythm restoration and monitored for complications post-procedure.
- Sinus rhythm achieved in 46 (84%) of 55 patients receiving 720 J.
- 18 patients (39%) maintained sinus rhythm over a mean follow-up of 2.1 months.
- No major complications or significant hemodynamic compromise was observed.
Study Design
Type
Observational (n=55)
Structured PICO
Does higher energy synchronized external direct current cardioversion (720 J) restore sinus rhythm in patients with atrial fibrillation refractory to standard energy cardioversion?
P
Population
55 patients with atrial fibrillation who failed to achieve sinus rhythm after at least two attempts at standard external cardioversion with 360 J. Mean weight 117 +/- 23 kg, structural heart disease present in 76%, mean LVEF 45 +/- 12%.
I
Intervention
Higher energy synchronized external direct current cardioversion using two external defibrillators delivering a synchronized total of 720 J.
O
Outcome
Restoration of sinus rhythmsurrogate
Higher energy synchronized external cardioversion (720 J) is a safe and effective alternative for restoring sinus rhythm in patients with atrial fibrillation refractory to standard 360 J cardioversion.
Abstract
OBJECTIVES: 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.