Step 1: Confirm < 48 hour onset or on effective anticoagulation

Step 2: Chemical Cardioversion:
        -Amiodarone (Cybulski et al): 53% converted to NSR in 8 hours, 83% converted to NSR in 20 hours
        -Procainamide (Stiell et al): 52% conversion to NSR usually in <1 hour, 94% discharge rate, 89% in NSR

Step 3: Electrical Cardioversion (Cohn et al): 85.5%-97% converted to NSR
        -Tips: Use AP pad placement, shave patient (if hairy), Start at 200J

Question: Is cardioversion safe? 
Answer: Yes, in the right patient population.  <48 hours from onset or effective anticoagulation for approximately 6 weeks.  If the patient is 'sick', treat the underlying disease!

Question: What about stroke risk? 
Answer: General recommendations: start all patients with a CHA2DS-VASc >/=1 on anticoagulation whether or not you cardiovert 

Question: How about rate control and discharge? 
Answer: Better for the elderly, minimally symptomatic, unclear time of onset or > 48 hours.  

Question: Metoprolol or Diltiazem?
Answer: Multiple studies show diltiazem is superior but avoid in CHF patients.  If effective, start diltiazem drip, give po beta blocker, titrate down drip then turn off drip.  Monitor for at least one hour.  If patient rate controlled, likely ok for discharge with close Cardiology outpatient follow-up.  

 References:
1. Cohn, BG, Keim SM, Yealy DM. Is emergency department cardioversion of recent-onset atrial fibrillation safe and effective? J Emerg Med. 2013 Jul;45(1):117-27.
2. Cybulski, J., Kulakowski, P., Andrzejbudaj, et al. Intravenous Amiodarone for Cardioversion of Recent-Onset Atrial Fibrillation. Clin. Cardiol. 26, 329–335 (2003).
3. Stiell IG, Clement CM, Brison RJ, et al. Variation in management of recent-onset atrial fibrillation and flutter among academic hospital emergency departments. Ann Emerg Med. 2011 Jan;57(1):13-21.
4. Stiell IG, Clement CM, Symington C, et al. Emergency department use of intravenous procainamide for patients with acute atrial fibrillation or flutter. Acad Emerg Med. 2007 Dec;14(12):1158-64