Early Repolarization in Normal Adolescents is Common

In adults with structurally normal hearts, the early repolarization pattern (ERP) on electrocardiogram (ECG) may be associated with an increased risk of sudden cardiac death. The prevalence and significance of the ERP in children is unknown. This study examines the prevalence of the ERP, the population in which it is found, and whether there exists any correlation with increased LV mass or family history of significant cardiac events. This was a secondary review of data obtained from healthy adolescents undergoing a limited ECG and transthoracic echocardiogram (TTE) as part of a cardiac screening study. Subjects were excluded if ECG revealed known arrhythmic syndromes or TTE revealed structural abnormalities. ERP was defined as (1) notching or slurring of the terminal QRS; (2) elevation of the QRS-ST junction ≥1 mV; and (3) upwardly concave positive T-wave. Left ventricular (LV) mass was defined as mass/height^2.7. Patient demographics, LV mass, family history of sudden death, arrhythmia, and/or ICD/pacemaker placement were compared for subjects with and without ERP on ECG. Data from 575 subjects (median age 15, range 13–18; 36% female; 93% Caucasian) were reviewed. The incidence of ERP was 40% (n = 228) and was seen in the inferior, lateral, or combination of these leads in 42, 10, and 48% of subjects with ERP, respectively. There was no difference in gender (p = 0.7), race (p = 0.7), age (p = 0.3), history of syncope (p = 0.2), LV mass (p = 0.8), family history of (a) sudden death (p = 0.5), (b) arrhythmia (p = 0.2), or (c) ICD/pacemaker requirement (p = 0.8) in subjects with ERP versus those without. However, a greater percentage of patients with ERP were noted to play football, when compared to those without ERP (34 vs. 13%, p < 0.001). ERP is common in healthy adolescents, and does not correlate with concerning personal/family history or elevated LV mass. Longitudinal studies are required to determine whether ERP in childhood confers an increased mortality risk.