Rapid cardioversion for acute atrial fibrillation

The incidence of atrial fibrillation has increased globally, in part because of modifiable risk factors.1 Acute atrial fibrillation, especially at a rapid rate, is often treated with pharmacological or electrical cardioversion to restore sinus rhythm in patients whose condition is symptomatic but stable. Vernakalant is a relatively recent addition to the armamentarium of class III antiarrhythmic agents and acts by inhibiting potassium and sodium currents, preferentially in the atria. It is approved in 41 countries, including the European Union as of 2010, Canada, and parts of Asia.Previous studies have focused on a 1:1 comparison between vernakalant and placebo23 or other antiarrhythmics, including amiodarone,4 ibutilide,5 or flecainide.6 In a linked study (doi:10.1136/bmj-2025-085632), Stiell and colleagues conducted an open label, randomised controlled trial comparing intravenous vernakalant with intravenous procainamide in 350 patients who presented with acute atrial fibrillation lasting between three hours and seven days (average <24 hours) across 12 Canadian emergency...