Balaji S, et al. - Researchers analyzed data from 446 children 20 years and younger (65% male; mean age 10.1 ± 5.7 years) suffering idiopathic hypertrophic cardiomyopathy to assess the predictors of lethal arrhythmic event (LAE) in these subjects. For patients having a secondary prevention implantable cardioverter-defibrillator (ICD) or primary prevention ICD with appropriate interventions, septal thickness, posterior left ventricular (LV) wall thickness, lower LV outflow gradient, and Q wave > 3 mm in inferior electrocardiographic leads were identified as risk factors. Age at ICD placement, LV posterior wall thickness Z score, and LV outflow gradient < 30 mm Hg were revealed as risk factors for SCD in multivariate analysis. Children vs adults had different risk factors for LAE. Conventional adult risk factors were of no importance in children.