Balaji S, et al. - Via analyzing data from 446 children ≤20 years (65% male, mean age 10.1 ± 5.7 years) with idiopathic hypertrophic cardiomyopathy (HCM) from 35 centers, researchers investigated factors predictive of lethal arrhythmic events (LAE) in pediatric HCM cases. Two groups were defined: Group 1 (HCM with LAE) having a secondary prevention ICD, or primary prevention ICD with appropriate interventions, and Group 2 (HCM without LAE) including patients having a primary-prevention ICD without appropriate interventions. Septal thickness, posterior left ventricular (LV) wall thickness, a lower left ventricular outflow gradient and Q wave > 3 mm in inferior ECG leads were the risk factors for group 1 by univariate analysis. Age at ICD, LV posterior wall thickness Z score, and LV outflow gradient < 30 mmHg were identified as risk factors for SCD by multivariate analysis. Overall, children seemed to have different risk factors for LAE than adults. In children, conventional adult risk factors were not important.