What is the treatment for atrial fibrillation (AFib)?

Treatment for Atrial Fibrillation

All patients with atrial fibrillation require anticoagulation based on stroke risk assessment and rate control as foundational therapy, with rhythm control reserved for symptomatic patients or those with hemodynamic instability. 1, 2

Immediate Assessment and Stabilization

Hemodynamic Status

• Perform immediate electrical cardioversion if the patient presents with hypotension, acute heart failure, ongoing chest pain, or altered mental status. 1, 3
• For hemodynamically stable patients, proceed with rate control and anticoagulation assessment. 3

Evaluate for Reversible Causes

• Check thyroid function, electrolytes (particularly potassium and magnesium), renal and hepatic function to identify correctable triggers. 1
• Screen for acute myocardial infarction, pulmonary embolism, alcohol intoxication, or active infection. 3

Anticoagulation Strategy (Priority #1)

Stroke Risk Assessment

• Calculate CHA₂DS₂-VASc score immediately: congestive heart failure (1 point), hypertension (1 point), age ≥75 years (2 points), diabetes (1 point), prior stroke/TIA/thromboembolism (2 points), vascular disease (1 point), age 65-74 years (1 point), female sex (1 point). 1, 2
• Initiate anticoagulation for CHA₂DS₂-VASc score ≥2; strongly consider for score ≥1. 1, 2

Anticoagulant Selection

• Direct oral anticoagulants (DOACs)—apixaban, rivaroxaban, edoxaban, or dabigatran—are preferred over warfarin due to lower intracranial hemorrhage risk. 1, 2, 4
• Use warfarin only for mechanical heart valves or moderate-to-severe mitral stenosis. 1
• For apixaban: 5 mg twice daily, or 2.5 mg twice daily if patient meets ≥2 of these criteria: age ≥80 years, weight ≤60 kg, creatinine ≥1.5 mg/dL. 1
• For warfarin: target INR 2.0-3.0 with weekly monitoring during initiation, then monthly when stable. 1, 5

Critical Anticoagulation Timing

• If AF duration >48 hours or unknown, provide 3 weeks of therapeutic anticoagulation before cardioversion, or perform transesophageal echocardiography to exclude left atrial thrombus. 1, 3
• Continue anticoagulation for at least 4 weeks post-cardioversion in all patients. 1, 3
• Never discontinue anticoagulation based on rhythm status alone—stroke risk persists even after successful cardioversion due to silent AF recurrences. 2, 3

Rate Control Strategy (Priority #2)

First-Line Rate Control Agents

For patients with preserved ejection fraction (LVEF >40%):

• Beta-blockers (metoprolol, esmolol) or non-dihydropyridine calcium channel blockers (diltiazem 60-120 mg three times daily or 120-360 mg extended release; verapamil 40-120 mg three times daily or 120-480 mg extended release) are first-line. 1, 2, 6
• These agents provide rapid onset and remain effective even during high sympathetic tone states (post-operative, acute illness, thyrotoxicosis). 1, 7

For patients with reduced ejection fraction (LVEF ≤40%):

• Use beta-blockers and/or digoxin (0.0625-0.25 mg daily); avoid diltiazem and verapamil due to negative inotropic effects. 1, 2

For patients with COPD or active bronchospasm:

• Use diltiazem 60 mg three times daily as first-line; avoid beta-blockers, sotalol, and propafenone. 1
• Beta-1 selective blockers in small doses may be considered cautiously. 8

Rate Control Targets

• Initial target: lenient rate control with resting heart rate <110 bpm. 1, 2, 3
• Reserve stricter control (resting heart rate <80 bpm) for patients with persistent AF-related symptoms despite lenient control. 1, 2

Combination Therapy

• If single-agent therapy fails, combine digoxin with beta-blocker or calcium channel blocker for better control at rest and during exercise. 1, 3
• Monitor carefully for bradycardia when using combination therapy. 2

Rhythm Control Strategy (Priority #3)

Patient Selection for Rhythm Control

• Consider rhythm control for: symptomatic patients despite adequate rate control, younger patients, new-onset AF, or those with AF-related heart failure. 1, 2, 4
• The landmark AFFIRM trial demonstrated no survival advantage of rhythm control over rate control, but rhythm control may improve quality of life in symptomatic patients. 8, 2

Electrical Cardioversion

• Immediate synchronized DC cardioversion is required for hemodynamic instability. 1, 3
• For scheduled cardioversion in stable patients, ensure 3 weeks of anticoagulation beforehand if AF duration >48 hours. 1, 3

Pharmacological Cardioversion and Maintenance

For patients without structural heart disease:

• Flecainide or propafenone are first-line options due to low proarrhythmic risk and minimal organ toxicity. 1, 2, 9, 10
• Propafenone is indicated to prolong time to recurrence of paroxysmal AF with disabling symptoms. 9
• Common pitfall: Propafenone can cause 1:1 AV conduction in atrial flutter, increasing ventricular rate—always use concomitant AV nodal blocking agents. 9

For patients with coronary artery disease:

• Sotalol is preferred unless heart failure is present. 1, 10

For patients with heart failure or LVEF ≤40%:

• Amiodarone is the only safe option due to low proarrhythmic risk in this population. 1, 10
• Can use IV amiodarone (300 mg diluted in 250 mL 5% glucose over 30-60 minutes) for acute situations. 1

For patients with hypertension and left ventricular hypertrophy:

• Avoid class III/IA agents due to increased torsade de pointes risk; amiodarone is preferred. 10

Catheter Ablation

• Consider catheter ablation as second-line therapy when antiarrhythmic drugs fail, or as first-line in selected patients with symptomatic paroxysmal AF. 1, 2, 4
• Catheter ablation is first-line therapy for patients with AF and heart failure with reduced ejection fraction (HFrEF) to improve left ventricular function, quality of life, and reduce mortality and heart failure hospitalization. 4
• Consider AV node ablation with pacemaker implantation only as last resort when all other rate and rhythm control strategies have failed. 2

Special Populations

Wolff-Parkinson-White Syndrome with Pre-excited AF

• Immediate DC cardioversion if hemodynamically unstable; IV procainamide or ibutilide if stable. 1
• Never use AV nodal blockers (adenosine, digoxin, diltiazem, verapamil, beta-blockers, amiodarone)—they can accelerate ventricular rate and precipitate ventricular fibrillation. 1
• Catheter ablation of accessory pathway is definitive treatment. 1

Post-Operative AF

• Beta-blockers or non-dihydropyridine calcium channel blockers for rate control. 1
• Preoperative amiodarone reduces incidence in high-risk cardiac surgery patients. 1

Permanent AF

• Focus exclusively on rate control and anticoagulation; do not attempt rhythm restoration. 1

Common Pitfalls to Avoid

• Never withdraw anticoagulation based on successful cardioversion or rhythm control—silent AF recurrences cause thromboembolic events. 2, 3
• Digoxin as sole agent is ineffective for rate control in paroxysmal AF; it works only at rest and fails during exercise or high sympathetic tone. 1, 6
• Underdosing anticoagulation or inappropriate discontinuation dramatically increases stroke risk. 1
• Using class I antiarrhythmic drugs (flecainide, propafenone) in patients with ischemic heart disease or structural heart disease increases risk of sustained ventricular arrhythmias. 10
• Performing catheter ablation without prior trial of medical therapy is not recommended except in specific populations (symptomatic paroxysmal AF, HFrEF). 1, 4

Monitoring and Follow-up

• Monitor renal function at least annually when using DOACs, more frequently if clinically indicated. 1
• For warfarin: INR monitoring weekly during initiation, then monthly when stable. 1, 5
• Reassess therapy periodically and evaluate for new modifiable risk factors (obesity, hypertension, sleep apnea, alcohol intake). 1, 2