Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) 3 is a rare arrhythmic disorder characterised by the overlapping features of both CPVT and Long QT Syndrome (LQTS). Affected patients exhibit adrenergic ventricular tachycardia with high prevalence of cardiac arrest and sudden cardiac death. They also suffer from recurrent atrial tachycardia which can trigger ventricular arrhythmias. Interestingly, patients have normal or mildly prolonged QTc at baseline with a paradoxical QT increase during adrenergic stimulation.Arrhythmic episodes are usually induced by exertion or stress. Affected individuals can suffer such episodes in early childhood, often resulting in sudden death. While CPVT has an overall prevalence of 1 in 10,000 individuals, CPVT3 has only been reported in a handful of families thus far. The condition does not have a gender or racial bias.
The disorder can be diagnosed based on clinical features and genetic analysis of the TECRL gene. Early diagnosis and management of CPVT3 is crucial in preventing cardiac episodes. Treatment includes the use of beta-blockers, flecainide therapy and implantable cardioverter defibrillators (ICDs). Genetic counselling is also recommended for asymptomatic family members of affected individuals.