Flecainide therapy suppresses exercise-induced ventricular arrhythmias in patients with CASQ2-associated catecholaminergic polymorphic ventricular tachycardia

• Published in: Heart rhythm Vol. 10; no. 11; pp. 1671 - 1675
• Main Authors: Khoury, Asaad, Marai, Ibrahim, Suleiman, Mahmoud, Blich, Miry, Lorber, Avraham, Gepstein, Lior, Boulos, Monther
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2013
• Subjects: Adolescent; Anti-Arrhythmia Agents - therapeutic use; Calsequestrin; Calsequestrin - genetics; Calsequestrin - metabolism; Cardiovascular; Catecholaminergic polymorphic ventricular tachycardia; Death, Sudden, Cardiac - prevention & control; DNA - genetics; Electrocardiography; Exercise Test - adverse effects; Female; Flecainide; Flecainide - therapeutic use; Follow-Up Studies; Humans; Male; Mutation; Tachycardia, Ventricular - drug therapy; Tachycardia, Ventricular - etiology; Tachycardia, Ventricular - genetics; Treatment Outcome; Young Adult; RyR2; Calsequestrin; CPVT2; CPVT; CASQ2; Catecholaminergic polymorphic ventricular tachycardia; ICD; Flecainide; VT; EIVA; calsequestrin-associated catecholaminergic polymorphic ventricular tachycardia; calsequestrin; exercise-induced ventricular arrhythmias; catecholaminergic polymorphic ventricular tachycardia; ventricular tachycardia; ryanodine receptor; implantable cardioverter-defibrillator
• ISSN: 1547-5271; 1556-3871; 1556-3871
• DOI: 10.1016/j.hrthm.2013.08.011

Calsequestrin-associated catecholaminergic polymorphic ventricular tachycardia (CPVT2) can cause sudden death in young individuals in response to stress. Beta-blockers are the mainstay medical treatment for patients with CPVT2. However, they do not prevent syncope and sudden death in all patients. Flecainide was reported to reduce exercise-induced ventricular arrhythmias (EIVA) in patients with ryanodine receptor-associated CPVT. The role of flecainide in CPVT2 is not known. To summarize our experience in combining flecainide and beta-blockers in high-risk patients with CPVT2. All patients with CPVT2 (10 patients) who have high-risk features (syncope, EIVA, or appropriate implantable cardioverter-defibrillator [ICD] shocks) despite beta-blockers with or without calcium channel blockers were treated with a combination of flecainide and beta-blockers. Exercise test was done before and after beginning treatment with flecainide. All patients had EIVA and 4 had appropriate ICD shocks before flecainide treatment. EIVA-included frequent ventricular premature beats and or ventricular tachycardia during the exercise test while on high dose of beta-blockers with or without calcium channel blockers before treatment with flecainide. After combination therapy with flecainide and beta-blockers, EIVA were suppressed completely in all patients. During follow-up of 15.5 ± 10.4 months (range 2–29 months), 8 patients were free of symptoms and free of arrhythmias. Two patients had 1 VT storm episode with recurrent ICD shocks despite repeated normal stress test. Flecainide can completely prevent ventricular arrhythmia during exercise and partially prevent recurrent ICD shocks in high-risk patients with CPVT2.