Management of Atrial Fibrillation
The initial management of atrial fibrillation (AF) should focus on three key objectives: rate control, prevention of thromboembolism, and consideration of rhythm control based on patient factors. 1
Initial Assessment and Diagnosis
Electrocardiogram (ECG) to:
- Confirm AF diagnosis
- Assess for LV hypertrophy, bundle branch block, prior MI
- Measure R-R, QRS, and QT intervals 2
Laboratory evaluation:
- Thyroid, renal, and hepatic function tests 2
Transthoracic echocardiogram to identify:
- Valvular heart disease
- Left atrial size
- Left ventricular function
- Evidence of structural heart disease 2
Rate Control Strategy
Rate control is typically the first-line approach for most patients with AF.
Recommended medications for rate control:
| Medication | IV Administration | Oral Maintenance Dose |
|---|---|---|
| Metoprolol | 2.5-5.0 mg IV bolus (up to 3 doses) | 25-100 mg BID |
| Diltiazem | 15-25 mg IV bolus | 60-120 mg TID (120-360 mg daily modified release) |
| Verapamil | 2.5-10 mg IV bolus | 40-120 mg TID (120-480 mg daily modified release) |
| Digoxin | 0.5 mg IV bolus | 0.0625-0.25 mg daily |
Important considerations:
- Beta blockers achieve target heart rate in 70% of patients vs. 54% with calcium channel blockers 1
- Avoid calcium channel blockers in patients with heart failure with reduced ejection fraction 1
- Digoxin should not be used as first-line therapy (only effective at rest) 1
- Combination therapy may be needed if single-agent therapy is insufficient 1
Stroke Prevention with Anticoagulation
Anticoagulation decisions should be based on the CHA₂DS₂-VASc score:
| CHA₂DS₂-VASc Score | Recommendation |
|---|---|
| 0 | No anticoagulation needed |
| 1 | Consider anticoagulation |
| ≥ 2 | Anticoagulation recommended |
Anticoagulation options:
- Direct oral anticoagulants (DOACs) are preferred over warfarin for non-valvular AF due to lower bleeding risk 3
- For patients with mechanical heart valves or mitral stenosis, warfarin is recommended with target INR 2.0-3.0 4
- Anticoagulation should continue for at least 4 weeks after cardioversion 1
Rhythm Control Strategy
Rhythm control should be considered for:
- Highly symptomatic patients despite adequate rate control
- Younger patients with fewer comorbidities
- Heart failure patients with reduced ejection fraction who remain symptomatic 1
Pharmacological cardioversion options:
- Intravenous flecainide or propafenone (for patients without structural heart disease)
- Intravenous vernakalant (excluding patients with recent ACS, HFrEF, or severe aortic stenosis)
- Intravenous amiodarone (for patients with structural heart disease) 1
Important safety note: If AF has been present for >24 hours, therapeutic anticoagulation for at least 3 weeks before cardioversion is required, or transesophageal echocardiography must be performed to exclude cardiac thrombus 1
Long-term rhythm control medications:
- Dronedarone
- Flecainide
- Propafenone
- Sotalol
- Amiodarone 1
Non-Pharmacological Options
- Catheter ablation: First-line therapy for symptomatic paroxysmal AF to improve symptoms and slow progression to persistent AF; also recommended for AF patients with heart failure with reduced ejection fraction 3
- Surgical approaches: May be considered during cardiac surgery for patients with preoperative AF 2
Lifestyle Modifications
All AF patients should be counseled on:
- Blood pressure control (target <140/90 mmHg)
- Weight management (target BMI 20-25 kg/m²)
- Regular physical activity (150-300 min/week moderate intensity)
- Alcohol reduction (≤3 standard drinks per week)
- Smoking cessation
- Management of comorbidities (hypertension, diabetes, sleep apnea) 1
Follow-up and Monitoring
- Regular cardiac monitoring to assess response to rate control therapy
- Regular neurological checks to monitor for stroke risk
- Patient education on signs and symptoms of stroke
- Follow-up visits within 10 days after discharge, at 6 months, and at least annually 1
Common Pitfalls to Avoid
- Inadequate anticoagulation: Never attempt cardioversion of AF lasting >24 hours without appropriate anticoagulation due to significant risk of thromboembolism
- Confusing rate control with rhythm control: Diltiazem and beta blockers control rate but do not convert AF to sinus rhythm
- Using aspirin alone for stroke prevention: Aspirin is not recommended for stroke prevention in AF as it has poorer efficacy compared to anticoagulation 3
- Overlooking heart failure: In patients with AF and heart failure with reduced ejection fraction, catheter ablation may improve quality of life and cardiovascular outcomes 3