What are the indications for the use of flecainide?

Indications for Flecainide Use

Flecainide is FDA-approved for prevention of paroxysmal supraventricular tachycardias (PSVT) including AVNRT and AVRT, paroxysmal atrial fibrillation/flutter with disabling symptoms, and life-threatening sustained ventricular tachycardia—but only in patients without structural or ischemic heart disease. 1

FDA-Approved Indications

Supraventricular Arrhythmias (Patients WITHOUT Structural Heart Disease)

• Paroxysmal supraventricular tachycardias (PSVT) including:

  • Atrioventricular nodal reentrant tachycardia (AVNRT) 1
  • Atrioventricular reentrant tachycardia (AVRT) 1
  • Other supraventricular tachycardias of unspecified mechanism associated with disabling symptoms 1

• Paroxysmal atrial fibrillation/flutter (PAF) associated with disabling symptoms 1

Ventricular Arrhythmias

• Documented life-threatening sustained ventricular tachycardia in the judgment of the physician 1
• Initiation must occur in hospital setting 1
• Not recommended for less severe ventricular arrhythmias even if symptomatic 1

Guideline-Based Treatment Algorithm

First-Line vs. Second-Line Status

• First-line agents for AVNRT/AVRT are beta-blockers, diltiazem, or verapamil 2
• Flecainide is a second-line treatment (Class IIa recommendation) for AVNRT/AVRT, used only when: 2
  • No structural heart disease is confirmed
  • No ischemic heart disease is present
  • First-line agents are ineffective or contraindicated
  • Patient is not a candidate for or refuses catheter ablation

Efficacy Data Supporting Use

• Renders sustained tachycardia non-inducible in 85% of patients with AVRT 2
• Achieves 93% probability of effective treatment (defined as <2 attacks) over 12 months in SVT patients without structural heart disease 3
• Shows superior long-term efficacy compared to verapamil for AVNRT (30% vs 13% complete symptomatic suppression) 2
• Only 24% recurrence rate versus 85% on placebo in controlled trials for PSVT 2
• Combination with beta-blockers increases efficacy to >90% for abolition of symptomatic tachycardia 2

Junctional Tachycardia

• May be reasonable (Class IIb recommendation) for ongoing management in patients without structural or ischemic heart disease who have junctional tachycardia 4
• Reduces automaticity from the ectopic focus in the AV junction 4

Absolute Contraindications

Critical Safety Exclusions

Flecainide is absolutely contraindicated in patients with structural heart disease or ischemic heart disease due to proarrhythmic risk demonstrated in the CAST trial, which showed increased mortality in post-MI patients with reduced left ventricular function 2, 3, 1, 5, 6

• Do not use in patients with recent myocardial infarction 1
• Not recommended in chronic atrial fibrillation (inadequately studied) 1
• Evaluate for any evidence of bundle-branch block or intraventricular conduction delay before initiating 3

Essential Monitoring and Precautions

Pre-Treatment Evaluation

• Confirm absence of structural heart disease through appropriate cardiac imaging 2, 3
• Exclude ischemic heart disease 2, 3
• Assess baseline ECG for PR interval, QRS duration, and conduction abnormalities 3

Combination Therapy

• Combination with beta-blockers is recommended to enhance efficacy and reduce risk of 1:1 AV conduction if atrial flutter develops 2
• Use adenosine with caution as it may precipitate atrial fibrillation with rapid ventricular rate in pre-excited tachycardias 2

Pediatric Considerations

• Used for supraventricular tachycardia in children without structural heart disease 7
• All children should have close monitoring with serial ECG and plasma levels during the first 48-72 hours after initiation 7
• Consider hospitalization for patients <1 year of age 7
• Has narrow therapeutic window with proarrhythmic effects even at therapeutic doses 7

Common Pitfalls to Avoid

• Never use in patients with structural or ischemic heart disease—this is the most critical safety consideration 2, 3, 1
• Do not assume normal baseline ECG excludes structural disease; imaging confirmation is required 2, 3
• Avoid in chronic atrial fibrillation (not adequately studied) 1
• Be aware of drug interactions, particularly with dairy products in children 7
• Monitor for proarrhythmic effects including ventricular arrhythmias, even with subjective improvement and normal QTc 8
• Requires caution in renal dysfunction with dose adjustment 6