The topic is very controversial and there is no agreement either on the continuous duration of a single episode or the total burden required to initiate AC. Most recommendations are expert opinions. I believe that 5 minutes is the most commonly accepted cutoff, which needs to be combined with an ass...

If there are multiple episodes of atrial fibrillation ranging in duration from 6 minutes to 6 hours with chadsvasc score of 2 or more, I would lean towards anticoagulation.