Atrial fibrillation is the most common arrhythmia encountered and managed in the emergency department.​​1,2​ In addition to ensuring hemodynamic stability and subsequent management of the arrhythmia, the emergency physician must identify and treat potential underlying causes. Atrial fibrillation itself may be a sequela of an underlying life-threatening disease process such as pulmonary embolism or sepsis. In some instances, treatment of the underlying cause may lead to the resolution of the arrhythmia.​​1​ It is …