Can flecainide be used to treat atrial fibrillation (AFib)?

Flecainide for Atrial Fibrillation Management

Flecainide is recommended for the treatment of atrial fibrillation in patients without structural heart disease, both for pharmacological cardioversion of recent-onset AF and for long-term rhythm control to prevent recurrence. 1

Indications and Patient Selection

Flecainide is specifically indicated for:

• Pharmacological cardioversion of recent-onset atrial fibrillation 1
• Long-term maintenance of sinus rhythm in paroxysmal AF 1, 2
• "Pill-in-the-pocket" approach for selected patients with infrequent, symptomatic episodes 1

Contraindications and Patient Safety

Flecainide must NOT be used in patients with:

• Structural heart disease 1, 2
• Heart failure with reduced ejection fraction (HFrEF) 1
• Coronary artery disease 1, 2
• History of myocardial infarction 2
• Severe left ventricular hypertrophy 1
• Cardiogenic shock 3
• Sinus or AV conduction disease (without pacemaker) 3, 2
• Brugada syndrome 3
• Chronic atrial fibrillation (not recommended) 2

Efficacy

• For acute cardioversion of recent-onset AF: 67-92% effective within 6 hours 1
• For long-term maintenance: Moderately effective for paroxysmal and persistent AF 4
• More effective than other antiarrhythmic drugs (except amiodarone) for acute termination of recent-onset AF 4, 5

Administration and Dosing

For pharmacological cardioversion:

• Intravenous: 2 mg/kg over 10 minutes 1
• Oral: 200-300 mg as a single dose 1

For long-term maintenance:

• Starting dose: 50 mg every 12 hours 3
• Maximum maintenance dose: 150 mg every 12 hours 3
• Dose adjustment for renal impairment: Reduce to 100 mg daily or 50 mg twice daily if creatinine clearance ≤35 mL/min 3

Monitoring and Safety Precautions

1. Obtain baseline ECG before initiation 3
2. Follow-up ECG after 3-5 days of therapy, at each dose change, and regularly thereafter 3
3. Monitor for QRS prolongation which may lead to QT prolongation 1
4. Consider concomitant AV nodal blocking agent (beta-blocker or calcium channel blocker) when using flecainide for atrial flutter to prevent 1:1 conduction 2
5. Maintain trough plasma levels between 0.2-1.0 mcg/mL 3

Potential Adverse Effects

• Proarrhythmic effects (7-8% of patients) 3, 6
• Potential for 1:1 atrioventricular conduction in atrial flutter 2
• Non-cardiac effects: dizziness, visual disturbances, headaches 3
• Increased mortality in patients with structural heart disease (based on CAST study) 2, 7, 8

Algorithm for Flecainide Use in AF

1. Patient Assessment:

   • Confirm diagnosis of paroxysmal or recent-onset AF
   • Rule out structural heart disease through echocardiography
   • Verify normal LV function (LVEF >40%)
   • Exclude coronary artery disease history

2. For Acute Cardioversion:

   • Ensure AF duration <48 hours or adequate anticoagulation
   • Administer IV flecainide 2 mg/kg over 10 min or oral 200-300 mg
   • Monitor ECG continuously during administration
   • Have resuscitation equipment available

3. For Long-term Maintenance:

   • Start at 50 mg twice daily
   • Titrate slowly based on response and tolerability
   • Maximum 150 mg twice daily
   • Add beta-blocker or calcium channel blocker to prevent rapid ventricular rates

4. Follow-up Monitoring:

   • ECG at baseline, 3-5 days, with each dose change, and periodically
   • Assess for symptoms of proarrhythmia (palpitations, syncope, dizziness)
   • Discontinue immediately if QRS widens >25% from baseline

Key Pitfalls to Avoid

• Using flecainide in patients with structural heart disease or coronary artery disease
• Failing to screen for structural heart disease before initiating therapy
• Not adding AV nodal blocking agents when treating atrial flutter
• Using flecainide for chronic atrial fibrillation
• Inadequate ECG monitoring during initiation and dose adjustments
• Continuing flecainide after development of structural heart disease

Flecainide remains an effective option for AF management in appropriately selected patients without structural heart disease, with a favorable risk-benefit profile when used according to guidelines.