Catecholaminergic polymorphic ventricular tachycardia

Professor, Lariboisiere University Hospital, Paris, France
Antoine Leenhardt

Primary ventricular tachyarrhythmias are rarely seen in children. Among them, catecholaminergic polymorphic ventricular tachycardia has a poor spontaneous outcome.
Catecholaminergic polymorphic ventricular tachycardia represents a clearly defined but still insufficiently recognized entity. Its rarity is matched only by its malignancy, and the consequence of misdiagnosis is sudden death in children with an otherwise normal heart.
They are responsible for syncope and include the risk of sudden death in young patients with no structural heart disease and a normal QT. Ventricular tachyarrhythmias are reproducibly induced by any form of sympathetic stimulation and should be looked for systematically in children presenting with convulsive fits or faintness triggered by exercise or emotion. Once the diagnosis is established, it is crucial to make the parents and the child (as early as possible) aware of the necessity of faultless compliance to the β-blocking therapy.
To date, autosomal dominant missense mutations in RYR2 (the gene encoding the cardiac ryanodine receptor type 2), and an autosomal recessive missense mutation in the cardiac calsequestrin gene (CASQ2) have been shown as the cause of the catecholaminergic polymorphic ventricular tachycardia. A total of 17 new mutations in the RYR2 and CASQ2 in 35 CPVT families have been found, indicating that pre-symptomatic detection of CPVT may be possible.