Treatment of Atrial Fibrillation
The treatment of atrial fibrillation follows the AF-CARE approach: Comorbidity management, Anticoagulation for stroke prevention, Rate or rhythm control for symptom management, and Evaluation with ongoing reassessment. 1
Initial Assessment and Classification
Atrial fibrillation (AF) is characterized by uncoordinated atrial activation with consequent deterioration of atrial mechanical function, presenting on ECG as replacement of consistent P waves with rapid oscillations or fibrillatory waves 1.
AF is typically classified as:
- Paroxysmal: Episodes lasting ≤7 days
- Persistent: Continuous episodes lasting >7 days
- Permanent: When a decision is made to no longer pursue rhythm control
Core Management Components
1. Anticoagulation for Stroke Prevention
Stroke risk assessment is critical for all AF patients:
- Calculate CHA₂DS₂-VASc score to assess thromboembolic risk 2
- For men with score ≥2 or women with score ≥3, anticoagulation is strongly recommended 2
- Direct oral anticoagulants (DOACs) are preferred over vitamin K antagonists 1, 2
- If DOACs are contraindicated, warfarin with target INR 2.0-3.0 is recommended 3
2. Rate Control Strategy
Rate control is recommended as initial therapy in the acute setting and as a long-term strategy 1:
- Target heart rate initially <110 bpm, optimal <80 bpm 2
- First-line medications for patients with LVEF >40% 1:
- Beta-blockers (metoprolol, esmolol, bisoprolol)
- Non-dihydropyridine calcium channel blockers (diltiazem, verapamil)
- Digoxin (particularly effective in sedentary patients or those with heart failure)
Medication dosing:
- Metoprolol: 2.5-5 mg IV bolus or 25-100 mg orally twice daily
- Diltiazem: 0.25 mg/kg IV over 2 minutes, then 5-15 mg/h, or 40-120 mg orally three times daily
- Digoxin: 0.25 mg IV every 2 hours (up to 1.5 mg) or 0.125-0.25 mg orally daily
Important cautions:
- Avoid non-dihydropyridine calcium channel blockers in heart failure with reduced ejection fraction 2
- Avoid calcium channel blockers and digoxin in patients with accessory pathways (WPW syndrome) 2
- Consider AV node ablation with pacemaker implantation for patients unresponsive to medical therapy 1
3. Rhythm Control Strategy
Consider rhythm control for:
- Symptomatic patients with persistent AF 1
- Patients within 12 months of diagnosis at risk of thromboembolic events 1
Options include:
- Electrical cardioversion (after appropriate anticoagulation if AF duration >24 hours) 1
- Pharmacological cardioversion with antiarrhythmic drugs
- Catheter ablation (particularly effective for paroxysmal AF and in heart failure patients) 4
4. Management of Comorbidities
Address underlying conditions that may contribute to AF:
- Hypertension
- Heart failure
- Diabetes
- Obesity
- Sleep apnea
- Thyroid dysfunction
Special Considerations
- For unstable patients, immediate electrical cardioversion is recommended 2
- Uncontrolled heart rate can lead to tachycardia-induced cardiomyopathy 2
- In patients with heart failure, optimize standard heart failure therapy alongside AF management 2
- Consider left atrial appendage occlusion for patients with contraindications to long-term anticoagulation 1
Monitoring and Follow-up
- Regular assessment of rate control adequacy, especially during exercise 1
- Periodic reassessment of stroke and bleeding risk 1
- Monitoring for medication side effects and interactions
- Evaluation for AF progression and development of complications
By following this comprehensive approach to AF management, focusing on stroke prevention, symptom control through rate or rhythm strategies, and addressing underlying conditions, patients can experience significant reductions in morbidity and mortality associated with this common arrhythmia.