5 points: Atrial fibrillation in the ER

1) The mainstay of management (in the ER) is rate control. If a patient has normal/near normal ejection fraction, both calcium channel blockers and beta blockers are effective agents. (The usual dose of diltiazem is 15 mg IV and metoprolol 5-10 mg IV). IV rate control meds wear off rapidly and consider sending home on an oral dose, even if you have achieved effective rate control.

2) In a patient with decompensated CHF and AF, amiodarone, digoxin or cautious beta blockers are the best options for rate control. Avoid calcium channel blockers as this may worsen the situation. Bedside ultrasound can be useful. 

3) Electrical or pharmacologic cardioversion is reasonable in patients with new onset afib (less then 48 hours and CHADS score <1, non valvular, no recent stroke). In patients with AFIB duration greater than 48 hours or high stroke risk, cardioversion in the ER should be deferred in most cases until the patient has been anticoagulated. 

4) Most patients who are cardioverted should receive oral anticoagulation for 4 weeks. This is true regardless of CHADS score. If possible, oral anticoagulation should be initiated prior to cardioversion .

5) Rapid AF can be a marker of an underlying problem, and other causes should be excluded (infection, heart failure etc). Prior to discharge, it is worthwhile to check liver, renal, coagulation panels and thyroid function especially before starting a DOAC.