Urgent rate control for atrial fibrillation

Urgent rate control of atrial fibrillation is rarely needed—oral therapy with the drugs listed in Rate control for atrial fibrillation is often sufficient for acute management. Urgent rate control may be required if the patient has significant symptoms, either due to acute new-onset atrial fibrillation or breakthrough rapid episodes in persistent atrial fibrillation.

Treat identifiable precipitants of the atrial fibrillation episode first and rule out the need for electrical cardioversion.

If urgent rate control for atrial fibrillation is required, consider using one of the following drugs under specialist advice, and with close blood pressure monitoringHindricks, 2021:

1metoprolol tartrate 2.5 to 5 mg intravenously over 2 minutes, repeated as required and tolerated up to a maximum of 3 dosesJanuary, 2014 metoprolol metoprolol metoprolol

OR

2esmolol 500 micrograms/kg intravenously, over 1 minute, followed by 50 to 300 micrograms/kg/min by intravenous infusion, titrated to achieve desired ventricular rateJanuary, 2014 esmolol esmolol esmolol

OR

3verapamil 2.5 to 10 mg intravenously, over 2 to 3 minutes, repeated as required and tolerated. verapamil verapamil verapamil

Verapamil is generally safe; however, it can occasionally cause profound depression of heart rate and/or contractility, particularly in patients who have pre-existing myocardial disease or those taking beta blockers.

Amiodarone can be useful for urgent rate control in patients with a left ventricular ejection fraction of 40% or less, or if the above drugs are not effective or tolerated. Intravenous loading is usually preferred over oral loading in the acute setting; however, the oral bioavailability of amiodarone is excellent and oral loading may also be rapidly effective (for the oral amiodarone loading dose, see Amiodarone for rate control of atrial fibrillation)NHFA CSANZ Atrial fibrillation guideline working group, 2018. A specialist may consider the following regimen:

amiodarone 300 mg by intravenous infusion over 30 to 60 minutes, followed by 900 mg by intravenous infusion over 24 hours, if requiredHindricks, 2021. amiodarone amiodarone amiodarone

Intravenous digoxin is not an optimal drug for urgent rate control in patients with atrial fibrillation; it slows the ventricular rate, but the onset of action is more than 1 hour and the effect does not peak for approximately 6 hoursNHFA CSANZ Atrial fibrillation guideline working group, 2018. In patients with atrial fibrillation without heart failure, intravenous digoxin is not more effective than placebo with respect to cardioversion or controlling rateJanuary, 2014January, 2019Jordaens, 1997.

Intravenous magnesium sulfate is also commonly used, but there is limited evidence to support its use in urgent rate control for atrial fibrillation.