Treatment Outcomes in Children With Catecholaminergic Polymorphic Ventricular Tachycardia: A Single Institutional Experience

Background and objectives: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a life-threatening inherited arrhythmogenic disorder. Recently, RYR2, the major CPVT-causative gene, was associated with neuropsychiatric manifestations. We aimed to analyze the clinical presentations, neuropsychiatric manifestations, and treatment outcomes of children with CPVT.

Methods: We retrospectively reviewed 23 patients diagnosed with CPVT before 19 years of age. Genetic analysis, history of neuropsychiatric manifestations, changes in ventricular arrhythmia burden before and after treatment, occurrence of cardiac events, and overall survival (OS) were investigated.

Results: RYR2 variants were identified in 17 patients, and 14 were classified as pathogenic or likely pathogenic. Neuropsychiatric manifestations, including intellectual disability and attention deficit hyperactivity disorder, were identified in 10 patients (43.5%). The 5-year cardiac event-free survival rate was 31.2%, and the 10-year OS rate was 73.1%. Patients diagnosed since 2009 had a higher cardiac event-free survival rate than those diagnosed before 2009 (p=0.0028). Combined beta-blocker and flecainide therapy demonstrated a lower risk of cardiac events than beta-blocker monotherapy (hazard ratio [HR], 0.08; 95% confidence interval [CI], 0.02-0.38; p=0.002). Left cardiac sympathetic denervation (LCSD) reduced the ventricular arrhythmia burden in Holter monitoring. Occurrence of near-fatal cardiac events after diagnosis was an independent predictor of death (HR, 33.40; 95% CI, 6.23-179.95; p<0.001).

Conclusions: Neuropsychiatric manifestations are common in children with CPVT. Flecainide and/or LCSD, when added to beta-blocker therapy, reduce the ventricular arrhythmia burden and cardiac events, thereby improving treatment outcomes in recent years.