Rate control in Atrial Fibrilation

• If LVEF<40% or any sign of CHF, smallest dose of beta-blocker is recommended to achieve rate control.
• Amiodarone is an option to patient with haemodynamic instability or severely reduced LVEF.
• If LVEF>40%, beta-blocker or diltiazem or verapamil are recommended because of its rapid onset of action and effectiveness at high sympathetic tone compared to digoxin.
• In both condition, digoxin may be added to achieve initial resting heart rate target which is <110bpm.

Therapy	Acute Intravenous rate control	Long-term oral rate control	Comments
Beta-Blocker
Bisoprolol	Not available	1.25–20 mg once daily or split.	Bronchospasm is rare – in cases of asthma, recommend beta-1 selective agents (avoid carvedilol). Contra-indicated in acute cardiac failure and a history of severe bronchospasm.
Carvedilol	Not available	3.125–50 mg BD.
Metoprolol	2.5–10 mg intravenous bolus (repeated as required)	100–200 mg total daily dose (according to preparation)
Nebivolol	Not available	2.5–10 mg once daily or split.
Esmolol	0.5 mg/kg intravenous bolus over 1 min; then 0.05–0.25 mg/kg/min.
Calcium Channel Blockers
Diltiazem	15–25 mg intravenous bolus (repeated as required)	60mg TDS up to 360mg total daily dose (120-360mg OD modified release)	Use with caution in combination with beta-blockers. Reduce dose with hepatic impairment and start with smaller dose in renal impairment. Contra-indicated in LV failure with pulmonary congestion or LVEF <40%.
Verapamil	2.5–10 mg intravenous bolus (repeated as required)	40-120mg TDS (120-480mg OD modified release)
Cardiac glycosides
Digoxin	0.5 mg intravenous bolus (0.75–1.5 mg over 24 hours in divided doses)	0.0625–0.25 mg daily dose	High plasma levels associated with increased risk of death. Check renal function before starting and adapt dose in patients with CKD. Contra-indicated in patients with accessory pathways, ventricular tachycardia and hypertrophic cardiomyopathy with outflow tract obstruction.
Digitoxin	0.4–0.6 mg intravenous bolus.	0.05–0.3 mg daily dose.
Specific Indications
Amiodarone	300mg intravenously diluted in 250mL 5% dextrose over 30-60 minutes via central venous cannula. *If ongoing requirement, 900mg diluted in 500-1000mL for over 24 hours.	200mg daily	Suggested as adjunctive therapy in patients where heart rate control cannot be achieved using combination therapy.

References:

1. 2016 ESC Guidelines for the management of atrial fibrillation
2. https://www.nice.org.uk/guidance/cg180/resources/atrial-fibrillation-management-pdf-35109805981381 
3. Pharmacologic Management of Newly Detected Atrial Fibrillation by AAFP, 2017
4. Lexicomp