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[Variance of signal-averaged electrocardiographic parameters with age in normal children]
1Department of Pediatrics, Asahikawa Medical College.
Insights
High-frequency components of the surface QRS complex were analyzed in children. QRS duration increased with age, while signal amplitude decreased, indicating developmental changes in cardiac electrical activity.
Area of Science:
- Pediatric Cardiology
- Biomedical Engineering
- Electrocardiography
Context:
- Surface electrocardiography (ECG) is crucial for assessing cardiac health in children.
- Quantitative analysis of high-frequency QRS components provides detailed insights into cardiac electrical activity.
- Understanding age-related changes in QRS parameters is essential for accurate interpretation of pediatric ECGs.
Purpose:
- To quantitatively analyze high-frequency components of the surface QRS complex in normal infants and children.
- To compare age-related differences in QRS duration and signal amplitude across four distinct age groups.
- To investigate the impact of varying high-pass filter frequencies on these measurements.
Summary:
- Eighty-seven healthy children aged 1 day to 15 years were divided into four age groups for analysis.
- Measurements included QRS duration, low-amplitude signal duration (U 40), and signal amplitudes (RMS; QRS, RMS 40) at 25, 40, 60, and 100 Hz filters.
- Results showed increasing QRS and U 40 durations and decreasing RMS amplitudes with age, with significant differences observed across groups.
Impact:
- Establishes normative data for high-frequency QRS components in pediatric populations.
- Highlights age-dependent electrophysiological changes in the developing heart.
- Provides a quantitative basis for interpreting ECG findings in pediatric cardiology and identifying potential abnormalities.
Abstract:
The high-frequency components of the surface QRS was analyzed quantitatively in 87 normal infants and children. The subjects were categorized in 4 groups by age; Group A: one day (n = 27), Group B: 1-5 years (n = 20), Group C: 6-10 years (n = 20), Group D: 11-15 years (n = 20), and the results were compared among the 4 groups. Signal-averaging and high-pass, bidirectional and digital filtering were used for analysis. The total duration of the QRS, the duration of the low-amplitude signals (< 40 microV) in the terminal portion of the QRS (U 40), the amplitude of the signals in the QRS (RMS; QRS) and the amplitude of the last 40 msec of the QRS (RMS 40) were measured at high-pass filter frequency settings of 25, 40, 60 and 100 Hz. Statistical analysis was performed with the unpaired t-test. Differences were considered significant if p < 0.05. The results were as follows: 1. At all filters, the durations of the QRS and U 40 were longer in the order of Groups A < B < C < D, and the amplitude of the RMS; QRS and RM 40 were greater in the order of Groups D < C < B < A. 2. There were significant differences in the QRS between the groups at all filters. 3. There were significant differences in U 40 between the groups except between Groups B and C at 25-Hz filter, but at 40-, 60-, 100-Hz filters, there were no significant differences among Groups B, C and D.(ABSTRACT TRUNCATED AT 250 WORDS)