Flecainide prevents catecholaminergic polymorphic ventricular tachycardia in mice and humans

Abstract

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome that is often difficult to treat. Hiroshi Watanabe and coworkers now show that flecainide, an approved drug known to inhibit sodium channels, is able to target the underlying cause of CPVT by inhibiting calcium release through the ryanodine receptor. Flecainide prevented arrhythmia in a mouse model of CPVT and was also effective when tested in two individuals with CPVT. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal inherited arrhythmia syndrome in which drug therapy is often ineffective. We discovered that flecainide prevents arrhythmias in a mouse model of CPVT by inhibiting cardiac ryanodine receptor–mediated Ca2+ release and thereby directly targeting the underlying molecular defect. Flecainide completely prevented CPVT in two human subjects who had remained highly symptomatic on conventional drug therapy, indicating that this currently available drug is a promising mechanism-based therapy for CPVT.