Prevalence and clinical significance of short PR interval in 1310 children and adolescent athletes: a cross-sectional study

Background
Children and adolescents represent a challenging population due to their incomplete physical development, and lack of specific criteria for interpreting electrocardiography (ECG) in children and adolescent athletes. We aimed to investigate the prevalence and clinical significance of short PR interval in pediatric and adolescent athletes undergoing pre-participation cardiac screening.

Methods
This is a cross-sectional study, where a total of 1310 athletes (age range: 7–18 years) underwent a comprehensive screening including medical history, physical examination, 12-lead ECG, echocardiography, and exercise testing under stress at Exercise and Sports Medicine Unit, University of Molise, Campobasso Italy between January 2023 and June 2024. Short PR interval prevalence and clinical significance were evaluated by frequency analysis and association with cardiac symptoms, respectively.

Results
Short PR interval (< 120 ms) was present in 26.9% of athletes, while using a z-score threshold of − 2 as the age- and sex-adjusted lower limit of normal, 3.82% of the athletes met criteria for a short PR interval. No significant associations were found between short PR interval and cardiac symptoms: syncope, palpitations, chest pain, exercise-induced arrhythmias, or need for additional diagnostic testing beyond standard screening (p > 0.05).

Conclusions
Isolated short PR interval was not associated with adverse cardiac findings among children and adolescent athletes following pre-participation screening, supporting its interpretation as a benign age-dependent variant. However, long-term outcome data are needed to confirm these observations.