What is the indication for Flecainide (antiarrhythmic medication)?

Flecainide Indications

Flecainide is indicated for the prevention of paroxysmal supraventricular tachycardias (PSVT) and paroxysmal atrial fibrillation/flutter in patients without structural heart disease, as well as for documented life-threatening ventricular arrhythmias. 1

Primary Indications

Flecainide is FDA-approved for:

1. Prevention of Supraventricular Arrhythmias (in patients without structural heart disease):

   • Paroxysmal supraventricular tachycardias (PSVT), including:
     • Atrioventricular nodal reentrant tachycardia (AVNRT)
     • Atrioventricular reentrant tachycardia (AVRT)
     • Other supraventricular tachycardias with disabling symptoms
   • Paroxysmal atrial fibrillation/flutter with disabling symptoms

2. Prevention of Ventricular Arrhythmias:

   • Documented life-threatening ventricular tachycardia

Treatment Algorithm and Positioning

For PSVT management:

1. First-line therapy: Catheter ablation (93-95% success rate)
2. First-line pharmacological therapy: Beta-blockers, diltiazem, or verapamil
3. Second-line pharmacological therapy: Flecainide or propafenone (when first-line agents are ineffective or contraindicated)

Flecainide has a Class IIa recommendation (reasonable to use) for ongoing management in patients with:

• AVNRT who are not candidates for catheter ablation or prefer medication
• Focal atrial tachycardia without structural heart disease
• Need for higher complete suppression rate (30% vs 13% for verapamil) 2

Efficacy

• 93% probability of effective treatment (defined as <2 attacks of arrhythmia in 12 months) for AVNRT 3
• 85-90% efficacy in preventing recurrent episodes of SVT in patients without structural heart disease 2
• Addition of a beta-blocker increases efficacy to >90% for symptomatic tachycardia abolition 2

Critical Contraindications

Flecainide is absolutely contraindicated in:

• Patients with structural heart disease
• Recent myocardial infarction
• Significant ventricular dysfunction
• Coronary artery disease

This contraindication is based on the CAST study, which demonstrated increased mortality with flecainide in post-MI patients with reduced left ventricular ejection fraction 4, 5.

Dosing Considerations

• Initial dose: 50 mg twice daily
• Can be increased in increments of 50 mg twice daily every 4 days
• Maximum dose: 300 mg/day 2
• Consider in-hospital initiation with rhythm monitoring for high-risk patients

Monitoring and Adverse Effects

Common adverse effects include:

• Visual disturbances
• Dizziness
• Headaches
• QRS widening (requires monitoring)

Serious but less common adverse effects:

• Proarrhythmic events (particularly in structural heart disease)
• New or worsened heart failure
• Bradyarrhythmias

Important Clinical Pearls

• Always rule out structural heart disease before initiating flecainide
• Flecainide can be used as "pill-in-the-pocket" therapy for selected patients, though evidence is limited 3
• Combining flecainide with beta-blockers requires careful monitoring due to risk of excessive bradycardia and AV block 2
• Minimally symptomatic patients with AVNRT may be considered for clinical follow-up without pharmacological therapy 3
• Flecainide is not recommended for chronic atrial fibrillation 1

The benefit-risk ratio should be carefully considered before initiating flecainide, as its use should be reserved for patients in whom the benefits of treatment outweigh the risks 1.