- History of symptomatic persistent or longstanding persistent AF Persistent AF - defined as continuous AF that is sustained more than 7 days but less than 12 months. Episodes of AF of ≥ 48 hours duration in which a decision is made to terminate with electrical or pharmacological cardioversion prior to 7 days will also be classified as persistent AF Longstanding persistent AF - defined as continuous AF of > 12 months and ≤ 3years of duration