What is the approach to managing atrial fibrillation?

Management Approach to Atrial Fibrillation

The management of atrial fibrillation should follow a structured approach focusing on three key strategies: rate control, rhythm control, and prevention of thromboembolism, with anticoagulation therapy based on stroke risk assessment using the CHA₂DS₂-VASc score. 1

Initial Assessment and Diagnosis

• Diagnostic workup:
  • 12-lead ECG to confirm atrial fibrillation
  • Echocardiogram to identify valvular heart disease, left atrial size, LV function, and structural abnormalities
  • Blood tests including thyroid function
  • Additional testing as needed: exercise testing, Holter monitoring, transesophageal echocardiography

Immediate Management

Hemodynamically Unstable Patients

• Immediate electrical cardioversion for patients with:
  • Acute MI
  • Symptomatic hypotension
  • Angina
  • Heart failure not responding to pharmacological measures 2

Hemodynamically Stable Patients

• Rate control strategy:

  • First-line medications:

    • Beta-blockers (metoprolol, bisoprolol, carvedilol)
    • Non-dihydropyridine calcium channel blockers (diltiazem, verapamil)
    • Digoxin (less effective during exercise, should be second-line) 1

  • Target heart rate: <110 bpm for lenient rate control 1

Long-term Management Strategies

1. Anticoagulation Therapy

• CHA₂DS₂-VASc score assessment:

  • Score 0: No anticoagulation needed
  • Score 1: Consider anticoagulation
  • Score ≥2: Anticoagulation recommended 1

• Anticoagulation options:

  • Direct oral anticoagulants (DOACs) preferred over vitamin K antagonists unless contraindicated
  • Warfarin with target INR 2.0-3.0 for non-valvular AF 3
  • For valvular AF (mechanical valves or mitral stenosis), warfarin is indicated 3

2. Rate Control vs. Rhythm Control

Rate Control Strategy

• Medications for rate control:

  Medication	IV Administration	Oral Maintenance Dose
  Metoprolol	2.5-5.0 mg IV bolus	25-100 mg BID
  Diltiazem	15-25 mg IV bolus	60-120 mg TID
  Verapamil	2.5-10 mg IV bolus	40-120 mg TID
  Digoxin	0.5 mg IV bolus	0.0625-0.25 mg daily

• Consider AV node ablation with pacemaker implantation for patients unresponsive to intensive rate control therapy 1

Rhythm Control Strategy

• Indications for rhythm control:

  • Young, symptomatic patients
  • First episode of AF
  • AF secondary to corrected precipitant
  • Heart failure exacerbated by AF
  • Pre-excited AF (WPW syndrome)
  • Pregnancy 1

• Cardioversion options:

  1. Electrical cardioversion:

     • Higher success rate compared to pharmacological methods
     • Preferred for persistent AF when early recurrence is unlikely 2
     • Biphasic shocks are most effective 4

  2. Pharmacological cardioversion:

     • Most effective when initiated within 7 days of AF onset 2
     • Options include:
       • Amiodarone (oral/IV): 1.2-1.8g/day in divided doses until 10g total, then 200-400mg/day maintenance 2
       • Flecainide (oral): 200-300mg for patients without structural heart disease 2
       • Propafenone (oral): 450-600mg for patients without structural heart disease 2
       • "Pill-in-the-pocket" approach with flecainide or propafenone for selected patients with infrequent episodes 1

• Maintenance of sinus rhythm:

  • Antiarrhythmic drugs based primarily on safety profile 2
  • Catheter ablation recommended for:
    • Paroxysmal or persistent AF resistant or intolerant to antiarrhythmic drugs
    • First-line option for symptomatic paroxysmal AF
    • Patients with AF and heart failure with reduced ejection fraction 1, 5

Special Considerations

Anticoagulation Around Cardioversion

• For AF >48 hours or unknown duration:
  • Anticoagulate for at least 3 weeks before cardioversion
  • Continue anticoagulation for at least 4 weeks after cardioversion 1

Periablation Anticoagulation

• Initiate at least 3 weeks prior to catheter ablation
• Maintain uninterrupted during the procedure
• Continue for at least 2 months post-ablation, regardless of rhythm outcome 1

Lifestyle Modifications

• Regular moderate physical activity (150-300 min/week)
• Weight management
• Limit alcohol consumption
• Blood pressure control
• Smoking cessation 1, 5

Follow-up

• First follow-up within 10 days of discharge
• Regular reassessment at 6 months after presentation, then at least annually
• Monitor for rate control adequacy, symptoms, and medication side effects 1