Late potentials in the signal-averaged electrocardiogram in pre-pubertal children with ADHD, before and after methylphenidate treatment

Reports on sudden cardiac death (SCD) of children and adolescents treated with stimulant agents have raised concerns regarding
the need for cardiovascular monitoring and risk stratification schedules. Cardiac ventricular late potentials (LPs) represent
delayed ventricular activation that might predispose to fatal ventricular arrhythmias and SCD in cardiac patients. LPs have
not previously been measured in children with attention deficit/hyperactivity disorder (ADHD). LPs were measured in 18 physically
healthy ADHD children (5 girls and 13 boys, age 11.9 ± 2.5 years, treatment duration 2.6 ± 1.9 years) before and 2 h after
oral methylphenidate administration. No significant changes were detected and LPs were found to be within normal ranges. In
conclusion, this preliminary small-scale study suggests that methylphenidate in physically healthy children with ADHD was
not associated with cardiac ventricular LPs, suggesting the safety of the agent in this age group.