Developmental trajectories of electrocardiographic parameters in pediatric patients.

BACKGROUND

Normative pediatric electrocardiographic (ECG) parameters have been established in prior studies but lack fine temporal resolution during early life. Accurate age-specific values are critical for diagnosis, risk stratification, and management of cardiovascular diseases (CVD).

OBJECTIVE

To derive high-temporal-resolution developmental trajectories of ECG parameters in early childhood and to evaluate disease-related deviations.

METHODS

Five ECG parameters (heart rate, QRS, PR, QT, and corrected QT) were retrospectively analyzed from 6967 patients at a large pediatric hospital. ECGs were included only if they were adjudicated as normal by a pediatric cardiologist. Patients were stratified into 45 age groups: neonates (1-35 days, 35 groups), infants (2-6 months, 5 groups), and young children (1-5 years, 5 groups). A sensitivity analysis ranked parameters by age dependence. z scores quantified deviations in developmental trajectories between the clinically CVD-free cohort and patients with unrepaired tetralogy of Fallot (n = 305).

RESULTS

All 5 ECG parameters demonstrated significant developmental shifts, with marked differences between early (1-8 days) and late neonates (9-35 days). Sensitivity analysis identified the neonatal period as the most dynamic stage of electrophysiological maturation, followed by slower changes in infancy and childhood. Patients with unrepaired tetralogy of Fallot exhibited deviations from CVD-free children, including altered heart rate, PR, and QRS in late neonates and corrected QT outliers (≥ 2 standard deviation) in 32.7% and 24.3% of early and late neonates, respectively.

CONCLUSION

High-temporal-resolution ECG trajectories define age-specific norms in early life and enable the detection of disease-related deviations, particularly during the dynamic neonatal period.