What is already known on this topic?
Atrial fibrillation is a common diagnosis in the emergency department. Patients who present with new-onset atrial fibrillation less than 48 hours or are on long term anticoagulation can be safely cardioverted in the emergency department. Patients who present with symptomatic atrial fibrillation longer than 48 hours and not on anticoagulation are traditionally admitted to the cardiology department for evaluation and treatment.