A novel marker of electrical instability in children with hypertension: cardiac electrophysiological balance index.

Background: Pediatric hypertension is a growing health concern, with prolonged exposure to high blood pressure potentially causing electrical instability and increasing arrhythmia risk. The index of cardiac electrophysiological balance (iCEB), calculated as QT interval divided by QRS duration, is a potential non-invasive marker for arrhythmogenesis. This study aimed to evaluate iCEB and corrected iCEB (iCEBc) in hypertensive children and investigate their relationship with arrhythmic risk.

Methods: This cross-sectional study included 81 children with primary hypertension and 36 age- and sex-matched healthy controls. Office blood pressure, 24-h ambulatory blood pressure monitoring (ABPM), standard echocardiography, and 12-lead electrocardiograms (ECGs) were obtained. QT, QTc, Tp-e, Tp-e/QT, Tp-e/QTc, iCEB, and iCEBc were calculated. Echocardiographic measurements and laboratory parameters were also evaluated.

Results: The mean age of the hypertensive group was 13.8 ± 3 years, with 60.5% males. Most (64.2%) demonstrated a non-dipping BP pattern. Echocardiography showed preserved ejection fraction (72.7 ± 5.4%) and shortening fraction (42 ± 5.1%), with left ventricular hypertrophy (LVH) observed in 8.6% of cases. ECG analysis revealed significantly prolonged QTc interval (416.8 ± 30.2 ms vs. 401.8 ± 23.4 ms; p = 0.008), iCEB (3.92 vs. 3.44; p = 0.02), and iCEBc (4.58 vs. 4.09; p = 0.001) values in hypertensive patients compared to controls. No significant differences were observed in Tp-e, Tp-e/QT, or Tp-e/QTc.

Conclusion: Children with hypertension exhibit subclinical alterations in cardiac electrophysiology, including significantly elevated iCEB and iCEBc values, which may indicate electrical instability and a higher arrhythmia risk. These indices may serve as practical, non-invasive tools for early detection of subclinical electrophysiological changes in pediatric hypertension.