Early repolarization in young children with attention-deficit/hyperactivity disorder versus normal controls: a...

Early repolarization (ER), considered a common and benign electrocardiographic pattern on the surface 12-lead electrocardiogram (ECG), was recently found to be prevalent among patients with idiopathic ventricular fibrillation. It is also highly predominant in physically active young males. Reports on sudden cardiac death (SCD) of children and adolescents treated with psychotropic agents have raised concerns regarding the need for cardiovascular monitoring and risk stratification schedules. The rate of ER pattern has not been estimated in children with attention deficit/hyperactivity disorder (ADHD). Thus, in the present retrospective chart review study, we estimated the rate of ER pattern, as well as RR, QT, and QTc intervals, from ECG tracings of physically healthy children with ADHD versus physically and mentally healthy controls.

The ECG tracings of 50 children (aged 8.7 +/- 1.4 years; 12 girls, 44 boys) diagnosed as suffering from ADHD were compared to 55 physically and mentally healthy controls (aged 8.25 +/- 2.1 years; 20 girls, 35 boys). ER was defined as an elevation of the QRS-ST junction (J point) of at least 0.1 mV from baseline with slurring or notching of the QRS complex, and assessed separately by two senior cardiologists who were blind to all other data relating to the study participants.

The rate of ER pattern was significantly higher in ADHD children compared to normal controls (32% vs. 13%, respectively, P = 0.012; relative risk [RR] = 1.68, 95% confidence interval [CI] 1.16-2.44), irrespective of stimulant treatment or gender. All other standard ECG measures (heart rate, QT and QTc intervals) were within normal range.

The rate of ER in children with ADHD is significantly higher than in normal controls. Its clinical significance awaits further research.