What is a recommended rate controller for atrial fibrillation (AF)?

Rate Control for Atrial Fibrillation

First-Line Agents

Beta-blockers or nondihydropyridine calcium channel blockers (diltiazem or verapamil) are the recommended first-line agents for rate control in atrial fibrillation. 1

Oral Therapy for Stable AF

• Metoprolol 25-100 mg twice daily is a preferred beta-blocker option for chronic rate control 2
• Diltiazem 120-360 mg daily (divided doses) or verapamil 120-360 mg daily (divided doses) are effective nondihydropyridine calcium channel blockers 2
• Atenolol is an alternative beta-blocker choice 2
• These agents control heart rate both at rest and during exercise, making them superior to digoxin monotherapy 1, 3

Intravenous Therapy for Acute AF with RVR

• IV diltiazem (0.25 mg/kg over 2 minutes, then 5-15 mg/hour infusion) achieves rate control faster than metoprolol and is highly effective 1, 4
• IV metoprolol (2.5-5 mg bolus over 2 minutes, up to three doses) is an alternative beta-blocker for acute settings 1
• IV esmolol (0.5 mg/kg over 1 minute, then 0.05-0.2 mg/kg infusion) provides ultra-short-acting beta-blockade with rapid reversibility 1
• IV verapamil (0.075-0.15 mg/kg over 2 minutes) is another calcium channel blocker option 1

Rate Control Targets

• Target resting heart rate <80 bpm for symptomatic management (strict control) 1
• Lenient control (resting heart rate <110 bpm) is reasonable if patients remain asymptomatic and left ventricular systolic function is preserved 1
• During moderate exercise, target heart rate should be 90-115 bpm 1, 2
• Assess rate control during exertion, not just at rest, as patients may have adequate resting control but excessive rate acceleration with mild activity 1

Special Clinical Scenarios

Heart Failure or Reduced LVEF

• Avoid nondihydropyridine calcium channel blockers (diltiazem, verapamil) in decompensated heart failure due to negative inotropic effects that can worsen hemodynamic compromise 1, 5
• Beta-blockers (metoprolol, carvedilol, atenolol) are preferred in patients with structural heart disease or reduced ejection fraction 3, 6
• Digoxin becomes more useful in heart failure patients, particularly when combined with beta-blockers 1, 3
• IV amiodarone is the preferred agent for rate control in critically ill patients or those with severe left ventricular dysfunction 1, 7

Hemodynamic Instability or Mild Hypotension

• Electrical cardioversion is indicated for hemodynamically unstable patients (systolic BP <90 mmHg or symptomatic hypotension) 1, 5
• IV amiodarone (300 mg over 30-60 minutes, then 900 mg over 24 hours) is preferred when mild hypotension is present, as it causes less hypotension than beta-blockers or calcium channel blockers 7, 5
• Avoid beta-blockers and calcium channel blockers in patients with overt volume overload or decompensated heart failure 5

Pre-excitation Syndromes (WPW)

• Do not use digoxin, nondihydropyridine calcium channel antagonists, or IV amiodarone in patients with pre-excitation and AF, as these may increase ventricular response and precipitate ventricular fibrillation 1
• Consider procainamide or ibutilide instead 7

Second-Line and Adjunctive Agents

Digoxin

• Digoxin is NOT recommended as monotherapy for rate control in active patients due to delayed onset (60 minutes to 2 hours) and ineffectiveness during exercise 1, 5, 3
• Digoxin is reasonable for sedentary patients, those aged ≥80 years, or as adjunctive therapy combined with beta-blockers or calcium channel blockers 2, 3, 8
• IV loading: 0.25 mg every 2 hours up to 1.5 mg total, then maintenance 0.125-0.25 mg daily 1, 9
• Oral maintenance dosing depends on renal function and lean body weight (typically 125-250 mcg daily) 9

Amiodarone

• IV amiodarone is useful for rate control in critically ill patients without pre-excitation 1, 7
• Dosing: 150 mg IV over 10 minutes, then 1 mg/min for 6 hours, then 0.5 mg/min; or 300 mg over 30-60 minutes followed by 900 mg over 24 hours 7, 5
• Oral amiodarone may be useful when other measures are unsuccessful or contraindicated 1
• Monitor for QT prolongation with amiodarone use 5

Combination Therapy

• Digoxin combined with beta-blocker or calcium channel blocker controls heart rate both at rest and during exercise more effectively than monotherapy 2
• When diltiazem infusion at maximum dose provides inadequate control, add IV amiodarone as the next step 7

When Pharmacologic Rate Control Fails

• AV nodal ablation with permanent ventricular pacing is reasonable when pharmacological therapy is inadequate and rhythm control is not achievable 1, 2
• Do not perform AV nodal ablation without prior attempts at pharmacologic rate control 1
• Consider catheter ablation of AF before proceeding to AV nodal ablation 8

Critical Contraindications

• Dronedarone should NOT be used to control ventricular rate in patients with permanent AF, as it increases risk of stroke, MI, systemic embolism, or cardiovascular death 1
• Nondihydropyridine calcium channel antagonists are contraindicated in decompensated heart failure 1
• Avoid digoxin, calcium channel blockers, and amiodarone in pre-excitation syndromes 1

Monitoring Parameters

• Assess rate control with 24-hour Holter monitoring to evaluate mean heart rate and circadian patterns 1, 2
• Perform exercise testing to ensure adequate rate control during activity 1, 2
• Monitor continuously for bradycardia and hypotension when using multiple rate-controlling agents 7
• Verify heart rate, blood pressure, and oxygen saturation during medication adjustments 7