What is the medical management of atrial fibrillation (Afib)?

Medical Management of Atrial Fibrillation

The medical management of atrial fibrillation requires a parallel approach addressing three core pillars: anticoagulation for stroke prevention, rate or rhythm control for symptom management, and treatment of underlying conditions—all guided by the patient's stroke risk profile, symptoms, and cardiac function. 1, 2

Stroke Prevention with Anticoagulation

Initiate oral anticoagulation for all patients with a CHA₂DS₂-VASc score ≥2 (or ≥1 in men, ≥2 in women by some scoring systems) to reduce stroke risk by 60-80%. 2, 3

Direct Oral Anticoagulants (DOACs) - Preferred First-Line

• Choose DOACs over warfarin in eligible patients due to lower intracranial hemorrhage risk and no need for routine monitoring 1, 2
• Standard DOAC regimens include:
  • Apixaban 5 mg twice daily (reduce to 2.5 mg twice daily if patient meets ≥2 of: age ≥80 years, weight ≤60 kg, creatinine ≥1.5 mg/dL) 2
  • Rivaroxaban, edoxaban, or dabigatran at standard doses unless specific reduction criteria met 2

Warfarin - When DOACs Contraindicated

• Use warfarin only in patients with mechanical heart valves or moderate-to-severe mitral stenosis 2
• Maintain INR 2.0-3.0 with weekly monitoring during initiation, then monthly when stable 2, 4

Critical Anticoagulation Timing

• For AF >48 hours or unknown duration: anticoagulate for ≥3 weeks before cardioversion and ≥4 weeks after 2, 4
• For AF <24-48 hours: most patients can be cardioverted on low molecular weight heparin without stroke risk 1
• Continue anticoagulation long-term based on stroke risk factors, regardless of whether patient remains in AF or converts to sinus rhythm 2, 4

Bleeding Risk Management

• Assess bleeding risk using HAS-BLED or similar tools, but do not withhold anticoagulation based on bleeding risk alone 1
• Address modifiable bleeding risk factors: uncontrolled hypertension, concomitant antiplatelet agents (discontinue aspirin/NSAIDs unless specifically indicated), alcohol excess, labile INR 1, 2
• Avoid combining anticoagulants with antiplatelet therapy unless acute vascular event (e.g., recent ACS or PCI) 1

Rate Control Strategy

Beta-blockers or non-dihydropyridine calcium channel blockers (diltiazem, verapamil) are first-line for rate control in patients with preserved ejection fraction (LVEF >40%). 2, 4

Rate Control by Cardiac Function

For LVEF >40%:

• Beta-blockers (metoprolol, bisoprolol, esmolol) OR
• 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) 2

For LVEF ≤40% or heart failure:

• Beta-blockers and/or digoxin 0.0625-0.25 mg daily 2, 4
• Avoid calcium channel blockers in reduced ejection fraction 4

Combination Therapy for Inadequate Control

• Add digoxin to beta-blocker or calcium channel blocker for better rate control at rest and during exercise 2, 4
• Never use digoxin as sole agent for paroxysmal AF—it is ineffective 4

Rate Control Targets

• Lenient control: resting heart rate <110 bpm is acceptable initial approach if patient asymptomatic and LVEF preserved 2
• Strict control: resting heart rate <80 bpm if symptoms persist with lenient strategy 2

Rhythm Control Strategy

Consider rhythm control for symptomatic patients, new-onset AF, or those with heart failure with reduced ejection fraction (HFrEF) to improve quality of life and cardiovascular outcomes. 1, 5

Immediate Cardioversion Indications

• Perform immediate electrical cardioversion for hemodynamic instability, severe heart failure, or pre-excited AF (WPW syndrome) 1, 2, 4
• In acute heart failure with AF: urgent rate control and often cardioversion required 1

Antiarrhythmic Drug Selection Algorithm

For patients WITHOUT structural heart disease:

• Flecainide, propafenone, or sotalol as first-line options 2, 4

For patients WITH coronary artery disease (but no heart failure):

• Sotalol is preferred first-line option 4

For patients WITH heart failure or LVEF ≤40%:

• Amiodarone or dofetilide ONLY—all other antiarrhythmics carry proarrhythmic risk 2, 4

For patients WITH hypertension without LV hypertrophy:

• Flecainide or propafenone may be used 4

Catheter Ablation

• Consider catheter ablation as first-line therapy for symptomatic paroxysmal AF to improve symptoms and slow progression to persistent AF 2, 5
• Recommend catheter ablation for AF patients with HFrEF to improve LV function, quality of life, and reduce mortality/heart failure hospitalization 5
• Use catheter ablation as second-line when antiarrhythmic drugs fail 2, 4

Initial Diagnostic Workup

Obtain the following baseline assessments before initiating therapy:

• 12-lead ECG to confirm AF diagnosis, assess ventricular rate, identify structural abnormalities 2, 4
• Transthoracic echocardiogram to identify valvular disease, left atrial size, LV function, structural abnormalities 2, 4
• Thyroid function (TSH), complete blood count, serum creatinine, urinalysis for proteinuria, blood pressure, fasting glucose to identify reversible causes 1
• Hepatic function tests in selected patients 1
• Stress test if signs or risk factors for coronary artery disease 1
• Coronary angiography if persistent LV dysfunction or myocardial ischemia signs 1

Special Populations and Situations

Postoperative AF

• Administer oral beta-blocker perioperatively to prevent postoperative AF after cardiac surgery 4
• Achieve rate control with AV nodal blocking agents if postoperative AF develops 4
• Peri-operative amiodarone is recommended where drug therapy desired for prevention 1

Pregnancy

• Immediate electrical cardioversion for hemodynamic instability or pre-excited AF 1
• Therapeutic anticoagulation with LMWH or VKAs (except first trimester or beyond week 36) for elevated thromboembolic risk 1
• Beta-1 selective blockers (excluding atenolol) for rate control 1

Wolff-Parkinson-White (WPW) Syndrome

• Perform catheter ablation of accessory pathway in symptomatic patients 4
• Immediate electrical cardioversion if rapid ventricular response with hemodynamic instability to prevent ventricular fibrillation 4

Structured Follow-Up and Reassessment

At each follow-up visit, systematically address:

• Has stroke risk profile changed? New diabetes, hypertension, or other CHA₂DS₂-VASc factors requiring anticoagulation initiation or continuation 1
• Are symptoms adequately controlled? If not, consider alternative rate/rhythm control therapy 1
• Monitor for proarrhythmia: Check ECG for PR, QRS, or QT prolongation, non-sustained VT, or pauses in patients on antiarrhythmics 1
• Has paroxysmal AF progressed to persistent/permanent? Consider alternative therapy 1
• Is rate control target achieved at rest and during exercise? 1
• Renal function assessment at least annually (more frequently if indicated) when using DOACs 2

Critical Pitfalls to Avoid

• Never underdose or inappropriately discontinue anticoagulation—this dramatically increases stroke risk 4
• Never use digoxin as sole agent for paroxysmal AF rate control—it is ineffective 4
• Never fail to continue anticoagulation after cardioversion in patients with stroke risk factors, regardless of rhythm 4
• Never administer type IC antiarrhythmics (flecainide, propafenone) in acute MI setting 4
• Never discharge patients within 12 hours of cardioversion 6
• Never use calcium channel blockers in patients with LVEF ≤40% 4

Lifestyle and Risk Factor Modification

Address modifiable risk factors at all stages to prevent AF onset, recurrence, and complications:

• Maintain optimal blood pressure with ACE inhibitors or ARBs as first-line therapy 1
• Maintain normal weight (BMI 20-25 kg/m²) 1
• Active lifestyle: 150-300 minutes/week moderate intensity or 75-150 minutes/week vigorous aerobic activity 1
• Avoid binge drinking and alcohol excess 1
• Optimize heart failure therapy in patients with HFrEF 1