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Relationship between QT and JT peak interval variability in prepubertal children
Yuka Takeuchi1, Yumi Omeki1, Kayo Horio1
1Graduate School of Health Sciences, Fujita Health University, Toyoake, Japan.
Summary
The J-point to Tpeak interval variability index (JTpVI) can reliably assess repolarization in infants, correlating strongly with the QT variability index (QTVI). This offers a new method for detecting early repolarization abnormalities in children.
Area of Science:
- Pediatric Cardiology
- Electrophysiology
- Autonomic Nervous System Function
Background:
- The QT variability index (QTVI) assesses autonomic nervous activity but is difficult to measure in children due to high heart rates.
- Accurate measurement of QT time is challenging in infants and young children.
Purpose of the Study:
- To establish standard values for the J-point to Tpeak interval (JTp) in infants by age.
- To assess the correlation between QT variability index (QTVI) and the JTp variability index (JTpVI).
Main Methods:
- Calculated QTVI and JTpVI from electrocardiograms of 623 infants/children (0-7 years) and 57 adults.
- Developed age-specific standard values, gender classification, and a growth curve for JTpVI.
- Subjects were stratified into three age groups for analysis.
Main Results:
- JTpVI demonstrated a significant decrease during infancy, gradually declining thereafter to reach adult levels by school age.
- A strong positive correlation (r = .856) was observed between JTpVI and QTVI.
- Age-specific standard values and a growth curve for JTpVI were successfully constructed.
Conclusions:
- The J-point to Tpeak interval variability index (JTpVI) is a viable alternative for assessing repolarization variability in healthy infants.
- JTpVI may serve as a valuable tool for the early detection of repolarization abnormalities in pediatric populations.
- This study provides normative data for JTpVI, facilitating its clinical application in children.
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