Polymorphic catecholergic ventricular tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmogenic disorder of the heart characterized by a reproducible form of polymorphic ventricular tachycardia induced by physical activity, stress, or catecholamine infusion, which can deteriorate into ventricular fibrillation. Patients present with recurrent syncope, seizures, or sudden death after physical activity or emotional stress. Typically, clinical cardiologic examinations, such as baseline ECG and echocardiogram, reveal mostly normal findings, and postmortem examinations, when carried out, have not disclosed any significant morphologic alterations in the fine structure of the heart, with the exception of mild fatty myocardial infiltration in a few patients. The hallmark of CPVT comprises ventricular arrhythmias of varying morphology not present under resting conditions but appearing only with physical exercise, excitement, or catecholamine administration. These arrhythmias are first seen as ventricular premature complexes, later in bigeminy, followed by bidirectional or polymorphic ventricular tachycardia, which eventually leads to ventricular fibrillation. CPVT can be inherited as an autosomal dominant or recessive trait. Clinical penetrance in this disease ranges from 25 to 100%, with an average of 70 to 80%. Syncope appears to be the first symptom in more than half of the patients. When untreated, mortality from CPVT is high, reaching 30 to 50% by the age of 30 years. Beta-blockers without sympathomimetic activity are clinically effective in the reduction of syncope, but implantation of an automatic internal defibrillator is occasionally needed in these patients (summary by {1:Bhuiyan et al., 2007}). Genetic Heterogeneity of Catecholaminergic Polymorphic Ventricular Tachycardia CPVT2 ({611938}) is caused by mutation in the CASQ2 gene ({114251}) on chromosome 1p13; CPVT3 ({614021}) has been mapped to chromosome 7p22-p14; CPVT4 ({614916}) is caused by mutation in the CALM1 gene ({114180}) on chromosome 14q32; and CPVT5 ({615441}) is caused by mutation in the TRDN gene ({603283}) on chromosome 6q22.

Source: Online Mendelian Inheritance in Man