RAFF4 Trial: Vernakalant vs. Procainamide for Acute Atrial Fibrillation in the Emergency Department

The objective is to compare IV vernakalant to IV procainamide for the ED management of acute AF patients. If vernakalant proves to be more effective, faster, and safer than IV procainamide, this will give clinicians an important alternative for pharmacological cardioversion of acute AF. The investigators propose a pragmatic comparative effectiveness trial entailing an open label, randomized controlled trial at 12 large Canadian EDs. Study subjects will be randomized to 1 of 2 treatment arms: 1) Patients will receive an initial infusion of 3mg/kg of IV vernakalant over 10 minutes, followed by a second dose of 2mg/kg over 10 minutes, if necessary, or 2) Patients will receive a continuous infusion of 15mg/kg of IV procainamide over 60 minutes. The primary aim will be to compare conversion to normal sinus rhythm between the two drugs. The investigators will include stable patients presenting with an episode of acute AF of at least 3 hours duration, where symptoms require urgent management and where immediate cardioversion is a reasonable option. Using the integrated consent model, research assistants will obtain verbal consent from eligible patients.