Association of the Ottawa Aggressive Protocol with rapid discharge of emergency department patients with recent-onset atrial fibrillation or flutter

CJEM. 2010 May;12(3):181-91. doi: 10.1017/s1481803500012227.


Objective: There is no consensus on the optimal management of recent-onset episodes of atrial fibrillation or flutter. The approach to these conditions is particularly relevant in the current era of emergency department (ED) overcrowding. We sought to examine the effectiveness and safety of the Ottawa Aggressive Protocol to perform rapid cardioversion and discharge patients with these arrhythmias.

Methods: This cohort study enrolled consecutive patient visits to an adult university hospital ED for recent-onset atrial fibrillation or flutter managed with the Ottawa Aggressive Protocol. The protocol includes intravenous chemical cardioversion, electrical cardioversion if necessary and discharge home from the ED.

Results: A total of 660 patient visits were included, 95.2% involving atrial fibrillation and 4.9% involving atrial flutter. The mean age of patients enrolled was 64.5 years. In total, 96.8% were discharged home and, of those, 93.3% were in sinus rhythm. All patients were initially administered intravenous procainamide, with a 58.3% conversion rate. A total of 243 patients underwent subsequent electrical cardioversion with a 91.7% success rate. Adverse events occurred in 7.6% of cases: hypotension 6.7%, bradycardia 0.3% and 7-day relapse 8.6%. There were no cases of torsades de pointes, stroke or death. The median lengths of stay in the ED were as follows: 4.9 hours overall, 3.9 hours for those undergoing conversion with procainamide and 6.5 hours for those requiring electrical conversion.

Conclusion: This is the largest study to date to evaluate the Ottawa Aggressive Protocol, a unique approach to cardioversion for ED patients with recent-onset episodes of atrial fibrillation and flutter. Our data demonstrate that the Ottawa Aggressive Protocol is effective, safe and rapid, and has the potential to significantly reduce hospital admissions and expedite ED care.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Arrhythmia Agents / adverse effects
  • Anti-Arrhythmia Agents / therapeutic use
  • Atrial Fibrillation / therapy*
  • Atrial Flutter / therapy*
  • Clinical Protocols*
  • Electric Countershock / adverse effects
  • Emergencies
  • Female
  • Humans
  • Length of Stay
  • Male
  • Middle Aged
  • Ontario
  • Procainamide / adverse effects
  • Procainamide / therapeutic use
  • Retrospective Studies
  • Safety
  • Treatment Outcome


  • Anti-Arrhythmia Agents
  • Procainamide