Early Repolarization in Pediatric Athletes: A Dynamic Electrocardiographic Pattern With Benign Prognosis.

Background Early repolarization pattern (ERP) is considered a common training-related and benign ECG finding in young adult athletes. Few data exist on ERP in the pediatric athletes population. Therefore, we aimed to evaluate the ERP prevalence, characteristics, and prognosis in pediatric athletes aged ≤16 years. Methods and Results Eight-hundred eighty-six consecutive pediatric athletes engaged in 17 different sports (mean age, 11.7±2.5 years; 7-16 years) were enrolled and prospectively evaluated with medical history, physical examination, resting and exercise ECGs, and transthoracic echocardiography during their preparticipation screening. Known cardiovascular diseases associated with sudden cardiac death was considered exclusion criteria. Athletes were followed up yearly for 4 years. The prevalence of ERP was 117 (13.2%), equally distributed in both sexes (=0.072), irrespectively of body mass index and classification of sports. The most common ERP localizations were inferolateral and inferior leads (53.8% and 27.3%, respectively). Notching J-point morphology was the most prevalent (70%), and rapidly ascending ST elevation (96%) was the most common ST-segment morphology. Athletes with ERP were older (<0.001) had lower rest and recovery heart rates (<0.001), increased precordial and limb R-wave voltages (<0.001), increased R/S Sokolow index (<0.001), and longer PR interval (=0.006) in comparison with the athletes without ERP. Neither major cardiovascular nor arrhythmic events, nor sudden cardiac death were recorded over a median follow-up of 4.2 years. One hundred seventeen (80.3%) athletes with ERP exhibited a persistent ERP. ERP localization and J-point morphology changed during follow-up in 11 (11.7%) and 17 (18%) of athletes, respectively. Conclusions ERP is common in pediatric athletes. It was mostly located in the inferolateral leads and associated with concave ascending ST segment with other training-related ECG changes. The lack of either sudden cardiac death or cardiomyopathies linked to sudden cardiac death over follow-up suggests that in pediatric athletes, ERP may be considered a benign training-related ECG phenomenon with a potential dynamic pattern.