Flecainide Reduces Ventricular Arrhythmias in Patients With Genotype RyR2-positive Catecholaminergic Polymorphic Ventricular Tachycardia

Abstract

Introduction and objectivesCatecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited disease characterized by polymorphic or bidirectional ventricular arrhythmias (VA) triggered by physical or emotional stress in young people with a structurally normal heart. Beta-blockers are the cornerstone of treatment, while flecainide has recently been incorporated into the therapeutic arsenal. The aim of this study was to report our experience with this drug. MethodsThe cohort included 174 genotype-positive CPVT-patients from 7 families. We collected data from patients who were receiving flecainide and analyzed the indications, adverse effects and dosage, clinical events, VA and arrhythmic window during exercise testing, and implantable cardioverter-defibrillator (ICD) shocks during follow-up. ResultsEighteen patients (10.4%) received flecainide; 17 patients in combination with beta-blockers, and 1 patient as monotherapy due to beta-blocker intolerance. None of the patients presented side effects. In 13 patients (72.2%) the indication was the persistence of exercise-induced VA and in 5 patients (27.7%) persistent ICD-shocks, despite on beta-blockers. After flecainide initiation, the exercise-induced VA quantitative score was reduced by more than 50% in 66.7% of the members of family 1 (32.76 ± 84.06 vs 74.38 ± 153.86; P = .018). The arrhythmic window was reduced (5.8 ± 11.9 bpm vs 19.69 ± 21.27 bpm; P = .007), and 4 of 5 patients with appropriate ICD shocks experienced no further shocks in the follow-up. ConclusionsIn CPVT-patients flecainide reduces clinical events, exercise-induced VA, the arrhythmic window, and ICD shocks, with good tolerance.