Catecholaminergic Polymorphic Ventricular Tachycardia Type 2 Presenting as Seizure in a Child: Diagnostic Pitfalls.

BACKGROUND

Catecholaminergic polymorphic ventricular tachycardia is a rare inherited arrhythmogenic disorder. In children, it is often misdiagnosed as epilepsy due to convulsive syncope triggered by exercise.

CASE SUMMARY: A 6-year-old boy presented with exercise-induced seizure-like episodes despite normal neuroimaging. Resting electrocardiogram and Holter were unremarkable, but exercise stress testing revealed bidirectional ventricular tachycardia. Genetic testing confirmed a homozygous CASQ2 mutation, consistent with catecholaminergic polymorphic ventricular tachycardia type 2. The patient was successfully managed with propranolol and flecainide, avoiding implantable cardioverter-defibrillator placement.

DISCUSSION: Catecholaminergic polymorphic ventricular tachycardia type 2 often presents earlier and more severely than type 1. This case highlights the importance of exercise testing in pediatric syncope with normal baseline findings and emphasizes genotype-phenotype correlation when managing incidental findings.

TAKE-HOME MESSAGES: Catecholaminergic polymorphic ventricular tachycardia type 2 should be considered in any child with exertional seizures despite normal baseline evaluations. Combination therapy provides an effective alternative to early implantable cardioverter-defibrillator implantation.