Is Flecainide (Flecainide) safe to use in a patient with a history of ventricular tachycardia (VTach)?

Flecainide is Contraindicated in Patients with History of Ventricular Tachycardia

Flecainide should not be used in patients with a history of ventricular tachycardia, even if it was a brief 2-second episode, due to significant risk of proarrhythmic effects and increased mortality. 1, 2

Rationale for Contraindication

Flecainide is a Class IC antiarrhythmic agent with potent sodium channel blocking properties that carries specific contraindications in patients with ventricular arrhythmias:

1. FDA Labeling: The FDA label explicitly states that flecainide should be reserved for patients with life-threatening ventricular arrhythmias where benefits outweigh risks, and should not be used for less severe ventricular arrhythmias even if symptomatic 1

2. Proarrhythmic Risk: Flecainide has significant proarrhythmic effects, particularly in patients with structural heart disease or history of ventricular arrhythmias 1, 2

3. CAST Trial Evidence: The Cardiac Arrhythmia Suppression Trial (CAST) demonstrated increased mortality with flecainide in post-MI patients with ventricular arrhythmias 1

Guidelines on Flecainide Use

The 2017 AHA/ACC/HRS guidelines for management of ventricular arrhythmias specifically state:

• "Based on CAST, flecainide is contraindicated in patients with ischemia, prior MI, and is avoided in patients with other structural heart diseases" 2

• "In the only large study of antiarrhythmic medications for congenital heart disease, the use of flecainide was associated with proarrhythmia in 5.8% of patients and SCA in 3.9% of patients" 2

The 2015 ESC guidelines further emphasize that flecainide should not be used in patients with structural heart disease and ventricular arrhythmias 2.

Alternative Treatment Options

For patients with a history of ventricular tachycardia, safer alternatives include:

1. Amiodarone: Has been shown to be safe in structural heart disease, particularly LV dysfunction 2

2. Sotalol: May be considered for some patients, though it also carries proarrhythmic risk 2

3. Catheter ablation: Should be considered for definitive treatment of ventricular tachycardia 2

Clinical Decision Algorithm

1. If patient has ANY history of VT (even brief):

   • Avoid flecainide completely
   • Consider amiodarone, sotalol, or catheter ablation based on cardiac function

2. If patient needs treatment for SVT but has history of VT:

   • Use AV nodal blocking agents (beta-blockers, calcium channel blockers)
   • Consider amiodarone if other options fail
   • Evaluate for catheter ablation of SVT

3. If patient has structural heart disease AND history of VT:

   • Absolutely avoid flecainide
   • Consider ICD placement based on ejection fraction and VT characteristics

Important Caveats

• Even a brief 2-second episode of VT indicates underlying myocardial vulnerability that could be exacerbated by flecainide 1, 2

• The proarrhythmic risk of flecainide is dose-dependent but present even at therapeutic doses 3, 4

• Research shows that patients with VT treated with flecainide have experienced aggravation of arrhythmias in approximately 20% of cases 4

• Mortality risk is particularly high in patients with structural heart disease and ventricular dysfunction 5

In conclusion, despite flecainide's effectiveness for supraventricular arrhythmias in patients without structural heart disease 6, its use in patients with any history of ventricular tachycardia represents an unacceptable risk and is contraindicated.