Catecholaminergic polymorphic ventricular tachycardia.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a highly lethal form of inherited arrhythmogenic disease characterized by adrenergically mediated polymorphic ventricular tachycardia. The mutations in cardiac ryanodine receptor and calsequestrin genes are responsible for the autosomal dominant and recessive variants of CPVT, respectively. The clinical presentation encompasses exercise- or emotion-induced syncopal events and a distinctive pattern of reproducible, stress-related, bidirectional ventricular tachycardia in the absence of both structural heart disease and a prolonged QT interval. The mortality rate in untreated individuals is 30-50% by age 40. Clinical evaluation by exercise stress testing and holter monitoring and genetic screening can facilitate early diagnosis. beta-adrenergic blockers are the most effective pharmacological treatment in controlling arrhythmias in CPVT patients, yet about 30% of patients still experience cardiac arrhythmias and eventually require an implantable cardioverter defibrillator.