Flecainide Contraindications
Flecainide is absolutely contraindicated in patients with structural heart disease, particularly coronary artery disease, previous myocardial infarction, or reduced left ventricular ejection fraction due to increased risk of mortality and proarrhythmia. 1, 2
Absolute Contraindications
- Pre-existing second- or third-degree AV block 2
- Right bundle branch block when associated with left hemiblock (bifascicular block), unless a pacemaker is present 2
- Cardiogenic shock 2
- Known hypersensitivity to flecainide 2
- History of myocardial infarction 1, 3
- Structural heart disease, particularly with reduced left ventricular function 1
- Decompensated systolic heart failure/LV dysfunction 1
Relative Contraindications and Precautions
Cardiac Conditions
- Sinus node dysfunction (risk of worsening sinus node activity) 1, 4, 5
- AV conduction disease (risk of complete heart block) 1, 4
- Wolff-Parkinson-White syndrome with atrial fibrillation/flutter 1
- Advanced disease of the His-Purkinje system 5
Non-Cardiac Conditions
- Renal dysfunction (flecainide is primarily eliminated through the kidneys) 1, 3, 4
- Hepatic dysfunction 1
Drug Interactions
- Concomitant use with drugs that have SA and/or AV nodal-blocking properties 1
- Significant interactions with: amiodarone, digoxin, verapamil, clarithromycin, cyclosporine, erythromycin, itraconazole, posaconazole, propafenone, voriconazole 1
Important Monitoring Considerations
- QRS duration should be monitored; an increase >25% from baseline indicates potential proarrhythmic risk requiring dose reduction or discontinuation 1
- Flecainide increases defibrillation energy requirements and pacing thresholds, requiring potential reprogramming of cardiac devices 1
- Flecainide can convert atrial fibrillation to slow atrial flutter with 1:1 AV conduction, which may be confused with ventricular tachycardia 1
Appropriate Use
Flecainide should only be used in:
- Patients without structural heart disease 1, 3
- Patients with supraventricular tachyarrhythmias who have failed or cannot tolerate beta-blockers, diltiazem, or verapamil 1, 6
- Carefully selected patients with atrial fibrillation for cardioversion, maintenance of sinus rhythm, or "pill-in-the-pocket" approach 1
Recent Evidence on Coronary Artery Disease
While traditionally contraindicated in all coronary artery disease, recent research suggests flecainide may be safe in selected patients with stable, non-obstructive coronary artery disease who have no history of myocardial infarction 7. However, this evidence is preliminary and the established guidelines still recommend avoiding flecainide in patients with any coronary artery disease 1, 3.