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Published on: April 29, 2013
Age-dependent Dynamics of the Electrocardiographic Parameters in Cardiovascular Disease-Free Children
Kazi T Haq1, Kathleen McLean1, Charles I Berul1,2,3
1Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, DC.
Insights
This study provides high-resolution electrocardiogram (ECG) parameters for neonates and infants, crucial for diagnosing cardiovascular diseases (CVD). The findings reveal significant ECG changes during early development, aiding in early disease detection.
Area of Science:
- Pediatric Cardiology
- Biomedical Engineering
- Developmental Pediatrics
Background:
- Standardized pediatric electrocardiogram (ECG) parameters lack temporal resolution for neonates and infants.
- Accurate ECG values are vital for diagnosing, stratifying risk, and managing cardiovascular diseases (CVD) in children.
Purpose of the Study:
- To establish high-temporal-resolution normative values for five key ECG parameters in neonates, infants, and young children.
- To analyze developmental shifts in ECG parameters and identify deviations in disease states.
Main Methods:
- Retrospective analysis of 7,346 ECGs from 6,967 pediatric patients with normal ECGs.
- Stratification into 45 age groups, including detailed neonatal (1-35 days) and infant (2-6 months) cohorts.
- Comparison of ECG trajectories between CVD-free patients and those with unrepaired tetralogy of Fallot (TOF) using Z-scores.
Main Results:
- Significant developmental shifts in all five ECG parameters (heart rate, QRS, PR, QT, QTc intervals) were observed across age groups.
- Neonatal ECG parameters showed rapid adaptation, with significant differences between early and late neonates.
- Unrepaired TOF patients exhibited distinct HR, PR, and QRS values compared to CVD-free children, with a high prevalence of outlier QTc values.
Conclusions:
- This study provides enhanced age-specific ECG reference values, particularly with day-level resolution for neonates.
- High-temporal-resolution ECG parameters can identify abnormal deviations, aiding in the diagnosis and management of early-life CVD.
- Developmental ECG trajectories serve as a valuable tool for detecting disease-related alterations in pediatric patients.
Background:
Normative pediatric electrocardiographic (ECG) parameters are standardized, but lack temporal resolution for neonates and infants. These values are clinically important, as they support the diagnosis, risk stratification, and management of cardiovascular diseases (CVD).
Methods:
Five ECG parameters (heart rate (HR), QRS, PR, QT, QTc intervals) were retrospectively analyzed from 7,346 recordings from 6,967 patients at a large pediatric hospital. Patients were only included if their ECG was adjudicated as normal by a pediatric cardiologist. Patients were assigned to 45 age groups: neonates (1-35 days, 35 groups), infants (2-6 months, 5 groups), and young children (1-5 years, 5 groups). Sensitivity analysis ranked ECG parameters to determine those most affected by age. Z-scores were used to quantify deviations in developmental ECG parameter trajectories in CVD-free patients compared with unrepaired tetralogy of Fallot (TOF, n=305).
Results:
Developmental shifts in ECGs were observed for all patients, irrespective of whether intensive care unit or CVD patients were included in the analysis. All five ECG parameters differed significantly between early (1-8 days) and late neonates (9-35 days). Sensitivity analysis revealed rapid ECG parameter adaptations during the neonatal stage, with slower changes during infancy and early childhood. Unrepaired TOF patients had significantly different HR, PR, and QRS values in the late neonatal group compared with CVD-free children. Z-scores revealed disease-specific deviations (≥ 2 SD of baseline), including outlier QTc values in 32.7% and 24.3% of early and late neonatal TOF patients, respectively.
Conclusion:
This study defined the values of five key ECG parameters, with enhanced age-specific resolution in neonates, infants, and children. Neonatal age emerged as the most dynamic stage for ECG parameter changes. This study demonstrated that high temporal resolution of age-specific ECG parameters can identify abnormal deviations, which can provide valuable insight for the diagnosis and management of CVD in early life.
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