anticoagulation prior to cardioversion of atrial fibrillation (AF)

Last edited 05/2021 and last reviewed 05/2021

Cardioversion of atrial fibrillation (AF) carries a moderate risk of thromboembolism in patients who have been in AF for more than 2 days.

In people with atrial fibrillation in whom the duration of the arrhythmia is greater than 48 hours or uncertain and considered for long-term rhythm control, delay cardioversion until they have been maintained on therapeutic anticoagulation for a minimum of 3 weeks. During this period offer rate control as appropriate


  1. NICE (April 2021). Atrial Fibrillation.