Pilot Randomized Trial With Flecainide in ARVC Patients

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is an inherited arrhythmia disorder with high risk of ventricular tachycardia or fibrillation, and implantable cardioverter defibrillator remains as therapy of choice. Antiarrhythmic therapy with different agents including beta-blockers, sotalol and amiodarone are usually not effective in reducing risk of arrhythmic events. Recent data indicated that flecainide effectively prevented the arrhythmias observed in the experimental ARVC animals and in small series of ARVC patients. These observations provide a strong rationale for conducting a pilot randomized clinical trial to determine whether flecainide will reduce ventricular arrhythmias in high-risk ARVC patients. This pilot study is designed as randomized double-blinded placebo-controlled crossover trial with administration of 100 mg of Flecainide or matching placebo twice a day for 4 weeks each with a washout period. Primary specific aim of this pilot trial is to determine whether Flecainide administration is associated with a significant reduction of number of ventricular ectopic beats (VEBs) in ARVC patients with implantable cardioverter-defibrillator (ICD). Secondary specific aims are: 1. to assess safety of flecainide administration with particular emphasis on proarrhythmic response measured by: 1. VEBs on ECG monitoring, 2. nonsustained and sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) episodes documented on ICD interrogation, and 3. effects of Flecainide on QRS morphology and duration. 2. to assess effects of flecainide on burden of VT runs in 7-day ECG recordings. 3. to assess effects of flecainide on burden of atrial premature beats in 7-day recordings. 4. to demonstrate feasibility of enrollment of rare inherited arrhythmia ARVC patients in a randomized study in the light of planned future large clinical trial with VT/VF/death as endpoint. Study population will include 38 ARVC patients diagnosed with the 2010 ARVC Task Force Criteria who are at least 18 years old, have implanted ICD, and show at least 500 VEBs in a 24-hour Holter recording. Patients on other pharmacological antiarrhythmic treatment other than beta-blockers and patients with prior catheter VT ablation will be excluded.