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Maturation of the QT Variability Index is Impaired in Preterm Infants

Arisa Kojima1, Tadayoshi Hata2,3, Tsuneaki Sadanaga4

  • 1Department of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan.

Pediatric Cardiology
|March 14, 2018
PubMed

Insights

The QT variability index (QTVI) is lower in preterm infants, indicating delayed cardiac autonomic nervous system development. This QTVI measurement correlates with gestational age, serving as an index of myocardial depolarization maturity.

Area of Science:

  • Neonatal cardiology
  • Autonomic nervous system development
  • Cardiac electrophysiology

Background:

  • Reduced heart rate variability in preterm infants suggests delayed autonomic cardiac control.
  • The relationship between myocardial repolarization development and gestational age is not well understood.

Purpose of the Study:

  • To investigate the association between the QT variability index (QTVI), a measure of myocardial repolarization lability, and the perinatal profile of healthy infants.
  • To assess QTVI as an indicator of cardiac autonomic nervous system maturity in relation to gestational age.

Main Methods:

  • Analysis of ECG variability indices, specifically the QT variability index (QTVI), in 209 healthy infants (143 boys, 87 girls).
  • Comparison of QTVI between 28 preterm infants (born before 37 weeks) and 181 control infants (born at term).
  • Statistical analysis to determine the correlation between QTVI and gestational age.

Main Results:

  • A significant negative correlation was found between QTVI and gestational weeks (r = -0.460, p = 0.035).
  • QTVI values were significantly higher in preterm infants compared to control infants (0.01 ± 0.50 vs. -0.26 ± 0.48, p = 0.023).

Conclusions:

  • The QT variability index (QTVI) is negatively correlated with gestational age in infants.
  • QTVI can serve as a valuable index for assessing the maturity of the cardiac autonomic nervous system and myocardial depolarization in neonates.

Keywords:
Cardiac autonomic nervous systemGestational agePreterm infantsQT variability index

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