What are the management options for atrial fibrillation?

Management of Atrial Fibrillation

Rate control with chronic anticoagulation is the recommended primary strategy for most patients with atrial fibrillation, as rhythm control has not demonstrated superiority in reducing morbidity and mortality. 1

Initial Assessment and Risk Stratification

• Confirm diagnosis with 12-lead ECG and immediately assess hemodynamic stability 2
• Calculate CHA₂DS₂-VASc score: congestive heart failure (1 point), hypertension (1 point), age ≥75 years (2 points), diabetes (1 point), prior stroke/TIA (2 points), vascular disease (1 point), age 65-74 years (1 point), female sex (1 point) 2
• Perform transthoracic echocardiography to evaluate left ventricular function, valvular disease, left atrial size, and structural heart disease 2
• Identify reversible causes: thyroid dysfunction, electrolyte abnormalities, hypoxemia, acidosis 3, 4

Stroke Prevention (Anticoagulation)

Direct oral anticoagulants (DOACs) are preferred over warfarin for all eligible patients with CHA₂DS₂-VASc score ≥2 due to lower intracranial hemorrhage risk. 3, 2

• Initiate oral anticoagulation for all patients with CHA₂DS₂-VASc score ≥2 unless contraindicated 1, 2
• Choose apixaban 5 mg twice daily (or 2.5 mg twice daily if ≥2 of: age ≥80 years, weight ≤60 kg, creatinine ≥1.5 mg/dL), rivaroxaban, dabigatran, or edoxaban over warfarin 2
• Rivaroxaban demonstrated non-inferiority to warfarin with hazard ratio 0.88 (95% CI: 0.74,1.03) for stroke or systemic embolism 5
• For patients on warfarin, maintain INR 2.0-3.0 with weekly monitoring during initiation and monthly when stable 3, 2
• Continue anticoagulation regardless of whether patient is in atrial fibrillation or sinus rhythm 4

Critical Anticoagulation Pitfalls

• Patients with AF lasting >48 hours or unknown duration require at least 3-4 weeks of anticoagulation before and after cardioversion 3, 4
• Never discontinue anticoagulation after cardioversion in patients with stroke risk factors 3, 4
• Underdosing anticoagulation or inappropriate discontinuation increases stroke risk 3, 4

Rate Control Strategy (First-Line for Most Patients)

Beta-blockers or non-dihydropyridine calcium channel blockers (diltiazem, verapamil) are first-line for rate control in patients with preserved ejection fraction (LVEF >40%). 1, 3, 2

Rate Control Medications by Clinical Scenario

Preserved Ejection Fraction (LVEF >40%):

• Atenolol, metoprolol, diltiazem (60-120 mg three times daily or 120-360 mg extended release), or verapamil (40-120 mg three times daily or 120-480 mg extended release) 1, 2
• Beta-blockers are effective at rest and during exercise 6

Reduced Ejection Fraction (LVEF ≤40%):

• Beta-blockers and/or digoxin are recommended 3, 4
• Avoid non-dihydropyridine calcium channel blockers 7

Obstructive Pulmonary Disease:

• Non-dihydropyridine calcium channel antagonists (diltiazem or verapamil) are preferred 3, 4
• Beta-1 selective blockers in small doses may be considered as alternative 3

Digoxin Limitations:

• Digoxin is only effective for rate control at rest and should only be used as second-line agent 1
• Digoxin is least effective but reasonable for physically inactive patients aged ≥80 years or as additional drug to other rate-controlling agents 7
• Combination of digoxin with beta-blocker or calcium channel antagonist provides better rate control at rest and during exercise 4

Rate Control Targets

• Target resting heart rate <110 bpm for lenient control or <80 bpm for strict control 2
• Lenient rate control (resting heart rate <110 bpm) is acceptable as long as patients remain asymptomatic and left ventricular function is preserved 2

Rhythm Control Strategy (For Selected Patients)

Rhythm control is appropriate when based on patient symptoms, exercise tolerance, and patient preference, but has not shown superiority to rate control in reducing morbidity and mortality. 1

Indications for Rhythm Control

• Symptomatic patients despite adequate rate control 3, 4
• New-onset atrial fibrillation 3, 4
• Hemodynamic instability (immediate electrical cardioversion mandatory) 3, 2

Cardioversion Approach

Hemodynamically Unstable:

• Immediate synchronized electrical cardioversion without waiting for anticoagulation 2

Stable Patients with AF <48 Hours:

• May proceed with cardioversion after initiating anticoagulation 2
• Both direct-current cardioversion and pharmacological conversion are appropriate 1

AF >48 Hours or Unknown Duration:

• Two options: transesophageal echocardiography with short-term anticoagulation followed by early cardioversion (if no thrombus) versus delayed cardioversion with 3-4 weeks pre- and post-anticoagulation 1, 3

Antiarrhythmic Drug Selection for Rhythm Maintenance

Most patients converted to sinus rhythm should not be placed on rhythm maintenance therapy since risks outweigh benefits. 1

No Structural Heart Disease:

• Dronedarone, flecainide, propafenone, or sotalol 8
• Critical Warning: Flecainide increased mortality in CAST trial (5.1% vs 2.3% placebo) in post-MI patients 9
• Flecainide is NOT recommended for chronic atrial fibrillation due to 10.5% rate of VT/VF 9
• Concomitant negative chronotropic therapy (digoxin or beta-blockers) required with flecainide to prevent 1:1 atrioventricular conduction 9

Abnormal Ventricular Function but LVEF >35%:

• Dronedarone, sotalol, or amiodarone 8

LVEF <35%:

• Amiodarone is the only drug usually recommended 8

Hypertrophic Cardiomyopathy:

• Restore sinus rhythm by direct current cardioversion or pharmacological cardioversion for recent-onset AF 3, 2
• Amiodarone (or disopyramide plus beta-blocker) to maintain sinus rhythm 3, 2
• Oral anticoagulation (INR 2.0-3.0) unless contraindicated 3, 2

Non-Pharmacologic Rhythm Control

• Catheter ablation should be considered when antiarrhythmic medications fail to control symptoms 3, 4
• Catheter ablation should be considered before atrioventricular node ablation 7
• "Pill in the pocket" approach: intermittent antiarrhythmic therapy may be considered in symptomatic patients with infrequent, longer-lasting episodes as alternative to daily therapy 8

Follow-up and Monitoring

• Reassess stroke risk factors at each visit: new diabetes, hypertension, heart failure 2
• Monitor INR weekly during warfarin initiation, then monthly when stable 2
• Evaluate renal function at least annually when using DOACs, more frequently if clinically indicated 2
• Record 12-lead ECG at each visit to document rhythm, rate, and assess for proarrhythmic ECG changes (PR, QRS, QT prolongation) 2
• Correct hypokalemia before initiating antiarrhythmic therapy 2
• Address modifiable risk factors: hypertension, obesity, sleep apnea, alcohol intake 4