What is the management of atrial fibrillation?

Management of Atrial Fibrillation

The management of atrial fibrillation should focus on stroke prevention through anticoagulation, rate or rhythm control strategies, and treatment of underlying conditions to reduce morbidity and mortality. 1

Initial Assessment and Diagnosis

• Diagnosis requires ECG documentation of the arrhythmia 2
• Classify AF as:
  • Paroxysmal (self-terminating within 7 days)
  • Persistent (lasting >7 days)
  • Permanent (accepted by patient and physician)
• Assess symptoms using EHRA score to quantify AF-related symptoms 2
• Evaluate for underlying causes:
  • Hypertension
  • Coronary artery disease
  • Valvular heart disease
  • Thyroid dysfunction
  • Heart failure
  • Diabetes mellitus

Immediate Management for Hemodynamically Unstable Patients

• Perform immediate electrical cardioversion for patients with:
  • Acute myocardial infarction
  • Symptomatic hypotension
  • Angina
  • Pulmonary edema
  • Shock 2, 1
• Do not delay cardioversion for anticoagulation in these emergency situations 2

Stroke Risk Assessment and Anticoagulation

• Use CHA₂DS₂-VASc score to determine stroke risk 1:

  • Score ≥2 in men or ≥3 in women: Anticoagulate indefinitely
  • Score of 1 in men or 2 in women: Consider anticoagulation
  • Score of 0 in men or 1 in women: No anticoagulation needed

• Anticoagulation options:

  • Direct oral anticoagulants (DOACs) are preferred first-line agents for non-valvular AF 1, 3
  • Warfarin (target INR 2.0-3.0) if DOACs are contraindicated 1
  • Avoid DOACs in patients with mechanical heart valves 4
  • Avoid DOACs in patients with triple-positive antiphospholipid syndrome 4

• Anticoagulation precautions:

  • Monitor INR at least weekly during initiation of warfarin therapy and monthly when stable 2
  • Consider lower INR target (1.6-2.5) for patients >75 years with bleeding risk 1
  • Reduce dabigatran dose to 75mg twice daily when used with dronedarone or ketoconazole in moderate renal impairment 4

Rate Control Strategy

• First-line agents:

  • Beta-blockers (preferred in most patients, especially with heart failure) 1, 5
  • Non-dihydropyridine calcium channel blockers (diltiazem, verapamil) in patients without heart failure 2, 1

• Medication dosing:

  • Metoprolol: 2.5-5 mg IV bolus or 25-100 mg orally twice daily 1
  • Esmolol: 500 μg/kg IV over 1 minute, then 50-300 μg/kg/min 1
  • Diltiazem: 0.25 mg/kg IV over 2 minutes, then 5-15 mg/h, or 40-120 mg orally three times daily 1
  • Verapamil: 0.075-0.15 mg/kg IV over 2 minutes, or 40-120 mg orally three times daily 1

• Second-line options:

  • Combination therapy with digoxin and beta-blocker or calcium channel blocker 2, 1
  • Amiodarone for rate control when other agents fail 1
  • AV nodal ablation with pacemaker implantation for refractory cases 1

Rhythm Control Strategy

• Consider rhythm control for:

  • Symptomatic patients despite adequate rate control
  • Younger patients
  • First episode of AF
  • AF secondary to corrected precipitant
  • Heart failure patients 3

• Cardioversion options:

  • Electrical cardioversion: Immediate option for hemodynamically unstable patients 2, 1
  • Pharmacological cardioversion: Class IC agents (flecainide, propafenone) for patients without structural heart disease 1
  • Amiodarone: 150 mg IV over 10 minutes, then 1 mg/min for 6 hours, followed by 0.5 mg/min 1
  • Ibutilide: 1 mg IV over 10 minutes, may repeat once 1

• Maintenance of sinus rhythm:

  • Amiodarone is most effective for maintaining sinus rhythm after conversion 2, 5
  • Catheter ablation for symptomatic patients who fail or cannot tolerate antiarrhythmic drugs 1, 3
  • Avoid class I antiarrhythmic drugs in patients with structural heart disease due to increased mortality risk 5

Special Considerations

• Hypertrophic cardiomyopathy:

  • Restore sinus rhythm by cardioversion in recent-onset AF 2
  • Use amiodarone or disopyramide plus beta-blocker for rhythm control 2
  • Consider catheter ablation for refractory AF 2

• Mechanical heart valves:

  • Dabigatran is contraindicated due to increased risk of thromboembolic events 4
  • Use warfarin with target INR 2.0-3.0 4

• Heart failure patients:

  • Prefer amiodarone over calcium channel blockers 1
  • Catheter ablation is recommended for patients with heart failure with reduced ejection fraction to improve outcomes 3

Follow-up and Monitoring

• Regular ECG monitoring to document rhythm and rate 2
• Assess for proarrhythmic ECG changes in patients on antiarrhythmic drugs 2
• Monitor for changes in stroke risk factors that may affect anticoagulation needs 2
• Evaluate symptom improvement and consider therapy changes if inadequate 2
• Follow-up within 1-2 weeks after discharge to reassess rhythm, rate control, and anticoagulation status 1

Lifestyle Modifications

• Weight loss and exercise are recommended for all stages of AF to prevent onset, recurrence, and complications 3
• Address modifiable risk factors (hypertension, diabetes, sleep apnea)