Evaluation of QT Interval Status in Low-Risk Children Presenting with Chest Pain During 2022–2023: A Cross-Sectional Study

Abstract

Introduction: Chest pain is for a frequent cause of pediatric outpatient visits and is predominantly attributable to non-cardiac etiologies. Nevertheless, given the uncommon yet potentially life-threatening risk of cardiac arrhythmias and sudden cardiac death, electrocardiography (ECG) is routinely included in the initial evaluation of these patients. The QT interval is a key ECG parameter used to detect ventricular repolarization abnormalities. However, available evidence has primarily focused on high-risk populations, while the diagnostic value of QT interval assessment in low-risk children with chest pain remains unclear. This study was designed to assess QT interval characteristics and determine the clinical utility of routine QT interval assessment in low-risk pediatric patients presenting with chest pain.

Methods: This cross-sectional analytical study included 80 children aged 5–14 years who presented with chest pain to the pediatric outpatient clinic of Amir-Al-Momenin Hospital in Semnan, Iran, between 2022 and 2024. Children with previously diagnosed structural or inherited cardiac diseases, arrhythmia syndromes, use of QT-prolonging medications, or systemic disorders affecting cardiac function were excluded. Standard 12-lead ECGs were obtained for all participants, and QT intervals were manually measured using the average of three to five consecutive cardiac cycles. Demographic and clinical data were collected. Statistical analyses were performed using SPSS version 16. Independent-samples t-test, Pearson correlation, and chi-square test were applied where appropriate.

Results: Among the 80 participants, 41 (51.3%) were boys and 39 (48.7%) were girls. The mean age was 8.94 ± 2.93 years, and the mean body weight was 30.36 ± 9.89 kg. The mean QT interval was 0.376 ± 0.026 seconds. Overall, 95% of the participants had QT intervals within the normal range, while 5% had borderline values; no abnormal QT interval was identified. No statistically significant differences in QT interval were observed according to sex, family history of cardiac disease, medication use, or underlying medical conditions (all P > 0.05). Furthermore, QT interval did not show a significant correlation with age, body weight, or any other demographic or clinical variable.

Conclusion: Routine measurement of the QT interval in low-risk children presenting with chest pain demonstrated limited additional diagnostic value, as QT intervals were almost uniformly normal and showed no significant association with demographic or clinical characteristics. These findings suggest that QT interval assessment should be interpreted within the context of comprehensive clinical evaluation, including medical history, family history, and warning symptoms, rather than being considered an isolated diagnostic indicator in low-risk pediatric patients.