Takeuchi Yuka, Omeki Yumi, Horio Kayo, Nishio Miki, Nagata Rina, Oikawa Shota, Mizutani Yuri, Nagatani Arisa, Funamoto Yuri, Uchida Hidetoshi, Fujino Masayuki, Eryu Yoshihiko, Boda Hiroko, Miyata Masafumi, Hata Tadayoshi
Graduate School of Health Sciences, Fujita Health University, Toyoake, Japan.
Department of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan.
Ann Noninvasive Electrocardiol. 2017 Jul;22(4). doi: 10.1111/anec.12444. Epub 2017 Feb 17.
The QT variability index (QTVI) is a noninvasive index of repolarization lability that has been applied to subjects with cardiovascular disease. QTVI provides a ratio of normalized QT variability to normalized heart rate variability, and therefore includes an assessment of autonomic nervous activity. However, measurement of QT time is particularly difficult in children, who exhibit physiologically high heart rates compared with adults. In this study, we developed a set of standard values of J-point to Tpeak interval (JTp) for infants by age, and assessed the correlation of QTVI with the JTp variability index (JTpVI).
Subjects included 623 infants and children (0-7 years of age) without heart disease and 57 healthy university students. All subjects were divided into three groups by age. QTVI and JTpVI were calculated based on an electrocardiogram, and age-specific standard values, a gender-specific classification, and a standard growth curve were constructed.
JTpVI markedly decreased in infancy and slowly decreased thereafter, reaching adult values by school age. There was also a strong correlation of JTpVI with QTVI (r = .856).
JTp can be used to evaluate the variability of the repolarization time in healthy infants, and may be useful for detection of early repolarization abnormalities.
QT变异性指数（QTVI）是一种复极易变性的无创指数，已应用于心血管疾病患者。QTVI提供了标准化QT变异性与标准化心率变异性的比值，因此包括对自主神经活动的评估。然而，QT间期的测量在儿童中特别困难，因为与成年人相比，儿童的心率在生理上较高。在本研究中，我们制定了一套按年龄划分的婴儿J点至T波峰间期（JTp）的标准值，并评估了QTVI与JTp变异性指数（JTpVI）的相关性。
研究对象包括623名无心脏病的婴儿和儿童（0至7岁）以及57名健康大学生。所有受试者按年龄分为三组。根据心电图计算QTVI和JTpVI，并构建年龄特异性标准值、性别特异性分类和标准生长曲线。
JTpVI在婴儿期显著下降，此后缓慢下降，到学龄期达到成人水平。JTpVI与QTVI也有很强的相关性（r = 0.856）。
JTp可用于评估健康婴儿复极时间的变异性，可能有助于早期复极异常的检测。
