Maturation of the QT Variability Index is Impaired in Preterm Infants

Abstract

Reduced heart rate (HR) variability in preterm infants compared with full-term infants suggests that autonomic cardiac control is developmentally delayed. However, the association between developmental changes in myocardial repolarization and gestational age remains unknown. This study investigated the association between the myocardial repolarization lability index, namely the QT variability index (QTVI) = log10 [(QTv/QTm2)/(HRv/HRm2)], and the perinatal profile of healthy 1-month-old infants. We included 209 infants (143 boys and 87 girls; mean gestational weeks at birth, 38.6 ± 1.7) who were born in university hospitals between 2014 and 2015 without apparent cardiac disease. We compared the ECG variability indices in 28 infants born before 37 gestational weeks (mean gestational weeks at birth, 35.6 ± 1.1 as preterm) and 181 infants born at the average number of gestational weeks (mean gestational weeks at birth, 38.8 ± 1.1 as controls). There was a negative correlation between the QTVI and gestational weeks (r = − 0.460, p = 0.035). QTVI values in preterm infants were larger than those in the controls (0.01 ± 0.50 vs. −0.26 ± 0.48, p = 0.023). In conclusion, the QTVI is negatively correlated with gestational age. The QTVI can serve as an index of the maturity of the cardiac autonomic nervous system and myocardial depolarization.

The echographic characteristics of structural and functional development of organs and systems in children born with low birth weight, very low birth weight and extremely low birth weight

“…Одним из этиологических факторов нарушения функционирования сердца может служить задержка созревания проводящей системы, а именно «вегетативного контроля» сердечной деятельности, о котором способно свидетельствовать снижение вариабельности сердечного ритма у недоношенных детей [51,52]. A. Kojima и коллеги (2018) изучали связь между реполяризацией миокарда, а именно вариабельностью интервала QT по данным электрокардиографии (ЭКГ), и гестационным возрастом.…”

“…В исследование были включены 181 здоровый доношенный младенец и 28 детей со сроком гестации менее 37 нед. Авторы сообщают об отрицательной корреляции между длительностью интервала QT в V1 и сроком гестации в 1 мес фактического возраста, что может свидетельствовать о незрелости вегетативной нервной системы сердца у недоношенных детей [52].…”

QT Variability Index is Correlated with Autonomic Nerve Activity in Healthy Children

“…This index changes with age in healthy children from infancy to school age [ 7 , 8 ]. In healthy 1-month-old infants, the QTVI is negatively correlated with gestational age, which can serve as an index of the maturity of the cardiac autonomic nervous system and myocardial repolarization [ 9 ]. In the present study, we examined the correlation between QTVI and the power spectral analysis parameters of HRV, which are commonly used to measure autonomic nerve balance.…”