Ottawa Aggressive Protocol: Treat and Street for Atrial Fibrillation?

It is another busy shift in the Emergency Department and you are seeing the third patient of the day in atrial fibrillation with rapid ventricular response. You think to yourself, “simple plan and disposition: stabilize, start on a diltiazem infusion, anticoagulate and admit to cardiology, right?” Well before you proceed with this well accepted approach, consider an alternative management strategy where you can even discharge the patient home!


Atrial fibrillation is one of the most common complaints presenting to the Emergency Department. Most emergency physicians are comfortable with the familiar treatment algorithms. A common thought-provoking branch point often includes which rate controlling medication to use (i.e. calcium channel blocker vs beta blocker). Today, we tackle a completely different question: Can I discharge my asymptomatic patient in atrial fibrillation if I am able to successfully achieve chemical cardioversion?


Stiell IG et al. Association of the Ottawa Aggressive Protocol with Rapid Discharge of Emergency Department Patients with Recent-Onset Atrial Fibrillation or Flutter. Canadian Journal of Emergency Medicine 2010; 12(3): 181-91


Question: What is the safety and efficacy of the Ottawa Aggressive Protocol for rapid discharge of Emergency Department patients with recent onset atrial fibrillation or atrial flutter?


Patients: Consecutive cohort of patients who presented to the ED with recent onset atrial fibrillation or flutter. Exclusion Criteria: Permanent AF, atrial fibrillation with duration > 48 hours or unknown duration


Intervention: Ottawa Aggressive Protocol: IV 1g procainamide infused over 60 minutes, if unsuccessful then electrical cardioversion. Full Protocol


Comparison: None


Conversion to sinus rhythm before discharge from ED
ED Length-of-Stay
Final disposition
Adverse events



  • 660 patients recruited (628 atrial fibrillation, 32 atrial flutter)
  • Procainamide successfully achieved cardioversion in 385/660 (58.3%)
  • Electrical Cardioversion attempted in 243 patients, successful in 223 patients
  • Discharge to home 639/660 (96.8%)
  • Discharge to home in NSR 595/660 (90.2%)
  • Adverse Events: Relapse rate at 7 days: 57/660 (8.6%)
  • Time to discharge/ED Length-of-Stay: Procainamide: 3.9 hours, Electrical Cardioversion: 6.5 hours

No comparison to standard care
Non randomized, non-blinded study
Patients were only followed for 7 days to investigate potential relapse rates and adverse events


Conclusions: The authors conclude that the Ottawa Aggressive Protocol is a safe and effective means of treating patients with new onset atrial fibrillation or atrial flutter and could potentially reduce ED length-of-stay and hospital admission rate. Remember this not applicable for patients who are symptomatic, unstable, or have an alternate etiology for their arrhythmia including ongoing ischemia, sepsis, etc.