Conditions: Catecholaminergic Polymorphic Ventricular Tachycardia
Keywords: Catecholaminergic Polymorphic Ventricular Tachycardia implantable cardioverter-defibrillator flecainide
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 14
Healthy volunteers: no

Brief summary:
The purpose of this study is to test whether the addition of oral flecainide to standard therapy will reduce ventricular ectopy on exercise test compared to placebo plus standard therapy in patients with Catecholaminergic Polymorphic Ventricular Tachycardia.

Detailed description:
Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is a genetic arrhythmia syndrome characterized by frequent ventricular ectopy and polymorphic, classically bidirectional ventricular tachycardia with physical or emotional stress, which also carries a risk of ventricular fibrillation and sudden death, despite no structural heart abnormality. Treatment consists of beta-blockers and/or calcium channel blockers, but up to 30% of patients require implantable cardioverter-defibrillators (ICDs) due to recurrent symptoms on medical therapy. In an animal model, flecainide was found to directly target the molecular defect in CPVT. In a retrospective clinical study in patients with CPVT we have seen improvement of ventricular ectopy on exercise tests when flecainide is added to standard therapy. We propose a prospective trial of flecainide added to standard therapy in CPVT patients to test the hypothesis that flecainide will reduce ventricular ectopy on exercise testing compared to placebo plus standard therapy.

This will be a single-blind (blinded subjects) randomized cross-over study, in which each patient will receive treatment A (flecainide or placebo) for at least 3 months and, after a 1 week wash-out, treatment B (placebo or flecainide) for at least 3 months.

Arms:
arm 1: In this crossover study, half of the subjects will be randomized to flecainide plus standard therapy with beta-blockers first, then crossover to placebo plus standard therapy with beta-blockers. arm 2: In this crossover study, half of the subjects will be randomized to placebo plus standard therapy with beta-blockers first, then crossover to flecainide plus standard therapy with beta-blockers.

Interventions: intervention 1: Flecainide Acetate intervention 2: Placebo intervention 3: Beta blocker
Intervention descriptions: intervention 1: oral flecainide with the dose titrated to achieve a serum level between 0.5-0.8 mcg/ml intervention 2: placebo, similar in appearance to flecainide intervention 3: Standard therapy with beta-blocker (nadolol, atenolol, metoprolol, or propranolol) continues throughout the trial.

Protocol document: