How to manage atrial fibrillation?

Management of Atrial Fibrillation

For all patients with atrial fibrillation, initiate oral anticoagulation with a direct oral anticoagulant (DOAC) such as apixaban or rivaroxaban as first-line therapy for stroke prevention, combined with rate control using beta-blockers or non-dihydropyridine calcium channel blockers (diltiazem or verapamil) in patients with preserved ejection fraction. 1, 2

Stroke Prevention: The Foundation of AF Management

Anticoagulation is mandatory for all AF patients with stroke risk factors, regardless of whether you pursue rate or rhythm control. 2

Anticoagulation Strategy:

• DOACs (apixaban, rivaroxaban, dabigatran, edoxaban) are preferred over warfarin due to significantly lower intracranial hemorrhage risk 2, 3
• Apixaban dosing: 5 mg twice daily (reduce to 2.5 mg twice daily if patient meets ≥2 of these criteria: age ≥80 years, weight ≤60 kg, creatinine ≥1.5 mg/dL) 3
• If warfarin is used, maintain INR 2.0-3.0 with weekly monitoring during initiation, then monthly when stable 1, 2, 4
• Continue anticoagulation indefinitely based on stroke risk factors—restoration of sinus rhythm does NOT eliminate stroke risk 2, 3

Cardioversion Anticoagulation Protocol:

• AF duration >48 hours or unknown: mandatory 3-4 weeks of therapeutic anticoagulation before cardioversion AND at least 4 weeks after 1, 2, 3
• Hemodynamically unstable patients: immediate cardioversion with concurrent heparin bolus followed by continuous infusion (aPTT 1.5-2× control), then oral anticoagulation for ≥3-4 weeks 1
• Alternative: TEE-guided cardioversion to exclude left atrial thrombus, but still requires post-cardioversion anticoagulation 1

Rate Control Strategy: First-Line for Most Patients

Rate control coupled with anticoagulation is the preferred initial strategy for most patients, as it provides equivalent outcomes to rhythm control with fewer adverse effects and lower costs. 5, 6, 7

Rate Control Medication Selection Algorithm:

For preserved LVEF (>40%):

• First-line: Beta-blockers (metoprolol, atenolol) OR non-dihydropyridine calcium channel blockers (diltiazem 60-120 mg TID or 120-360 mg extended-release; verapamil 40-120 mg TID or 120-480 mg extended-release) 1, 2, 3, 8
• Beta-blockers are particularly effective and should be considered first-line given their favorable mortality effects 9, 7
• Combination therapy (digoxin + beta-blocker or calcium channel blocker) provides superior rate control during both rest and exercise 1, 2, 3

For reduced LVEF (≤40%) or heart failure:

• Use beta-blockers and/or digoxin ONLY—calcium channel blockers are contraindicated 1, 2, 3
• Digoxin dosing: 0.0625-0.25 mg daily 3
• Beta-blockers are preferred for stabilized heart failure; digoxin for unstabilized forms 7

For obstructive pulmonary disease/active bronchospasm:

• Prefer diltiazem or verapamil; avoid non-selective beta-blockers 2, 3
• Beta-1 selective agents (metoprolol, atenolol) may be used cautiously in small doses 1, 3

For acute/emergency rate control:

• IV beta-blocker (esmolol 0.5 mg/kg bolus over 1 min, then 0.05-0.25 mg/kg/min) or IV diltiazem 1, 3
• IV amiodarone (300 mg in 250 mL 5% glucose over 30-60 minutes) for critically ill patients or when other agents fail 1, 3
• Immediate electrical cardioversion for hemodynamic instability (hypotension, angina, acute MI, pulmonary edema) 1

Rate Control Targets:

• Resting heart rate <80 bpm for symptomatic management 1, 2
• Lenient control (<110 bpm) is acceptable if patients remain asymptomatic and LVEF is preserved 1, 3
• Assess rate control during exercise, not just at rest—adjust medications to maintain physiological range during activity 1, 2

Critical Pitfall: Never use digoxin as monotherapy for rate control in active patients—it is only effective at rest and fails during exercise. 1, 2

Rhythm Control Strategy: For Selected Patients

Consider rhythm control for: symptomatic patients despite adequate rate control, new-onset AF, younger patients without significant comorbidities, or when AF contributes to heart failure decompensation. 2, 3, 6

Antiarrhythmic Drug Selection by Cardiac Structure:

No structural heart disease:

• Flecainide, propafenone, or sotalol 1, 2, 3

Coronary artery disease (without heart failure):

• Sotalol as first-line 3

Heart failure or LVEF ≤35-40%:

• Amiodarone is the ONLY safe option 1, 2, 3
• Dofetilide is an alternative in the US 3

Hypertension without left ventricular hypertrophy:

• Flecainide or propafenone 3

Hypertrophic cardiomyopathy:

• Amiodarone (or disopyramide plus beta-blocker) for rhythm maintenance 1, 2
• Immediate cardioversion (electrical or pharmacological) for recent-onset AF 1, 2
• Oral anticoagulation (INR 2.0-3.0) is mandatory unless contraindicated 1, 2

Cardioversion Approach:

• Electrical cardioversion is mandatory for hemodynamic instability 1, 3
• Pharmacological options: flecainide or propafenone for patients without structural heart disease 3
• Always ensure 3-4 weeks pre-cardioversion anticoagulation if AF duration >48 hours 1, 2

When Medications Fail:

• AV nodal ablation with permanent ventricular pacing is reasonable when pharmacological therapy is inadequate and rhythm control is not achievable 1, 2
• Catheter ablation should be considered before AV nodal ablation 1, 8
• Never perform AV nodal ablation without prior attempts at medical rate control 1

Special Clinical Scenarios

Wolff-Parkinson-White Syndrome with AF:

• Immediate DC cardioversion if hemodynamically unstable 2, 3
• If stable: IV procainamide or ibutilide 1, 2
• NEVER use AV nodal blockers (adenosine, digoxin, diltiazem, verapamil, beta-blockers, amiodarone)—they accelerate ventricular rate and can precipitate ventricular fibrillation 1, 2, 3
• Catheter ablation of the accessory pathway is definitive treatment to prevent sudden cardiac death 1, 2

Postoperative AF:

• Beta-blocker or non-dihydropyridine calcium channel blocker for rate control 3
• Preoperative amiodarone reduces incidence in high-risk cardiac surgery patients 3

High catecholamine states (acute illness, post-op, thyrotoxicosis):

• Beta-blockers are preferred 3

Prosthetic heart valves:

• Warfarin is mandatory (DOACs contraindicated) 1, 4
• Target INR 2.5-3.5 or higher depending on valve type and position 1, 4

Critical Management Pitfalls to Avoid

• Underdosing or inappropriately discontinuing anticoagulation dramatically increases stroke risk 2, 3
• Attempting cardioversion without 3-4 weeks of anticoagulation when AF duration >48 hours 1, 2, 3
• Failing to continue anticoagulation after successful cardioversion in patients with stroke risk factors—sinus rhythm does not eliminate stroke risk 2, 3
• Using digoxin as sole agent for rate control in paroxysmal AF or active patients 1, 2
• Using calcium channel blockers in decompensated heart failure or reduced LVEF 1, 2
• Performing catheter ablation without prior medical therapy trial 1
• Using AV nodal blockers in Wolff-Parkinson-White syndrome with pre-excited AF 1, 2, 3

Monitoring Requirements

• INR monitoring for warfarin: weekly during initiation, monthly when stable 1, 2, 4
• Renal function assessment at least annually with DOACs, more frequently if clinically indicated 3
• Reassess anticoagulation need regularly, but continue indefinitely based on stroke risk factors 1, 3
• Exercise testing and 24-hour Holter monitoring to assess adequacy of rate control during daily activities 1, 7