Beat-to-beat QT interval variability in children: Normal and physiologic data

Hirofumi Kusuki, Marina Kuriki, Kayo Horio, Misa Hosoi, Hideaki Matsuura, Masayuki Fujino, Yoshihiko Eryu, Masafumi Miyata, Toshiaki Yasuda, Toshio Yamazaki, Shunji Nagaoka, Tadayoshi Hata

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Background: QT interval variability provides information on ventricular vulnerability. However, QT interval variability in children has not been adequately evaluated. Methods: One hundred seventy-three consecutive nursing infants and children (male-female, 106:67) up to school age with no intrinsic cardiac disease were included in this study, and they were categorized into 6 age-related groups. The QT variability index (QTVI) was calculated based on an electrocardiogram; and age-specific standard values, sex-specific classification, and a standard growth curve covering 0 to 7 years were constructed. Results: The QTVI decreased in an age-dependent manner, reached constant values after school age, and exhibited no sex-specific differences in 6 age-related groups. Conclusions: Based on the age-dependent standardized QTVI values, it is possible to estimate the instability of ventricular repolarization in pediatric patients with better accuracy.

Original languageEnglish
Pages (from-to)326-329
Number of pages4
JournalJournal of Electrocardiology
Issue number3
Publication statusPublished - 01-05-2011


All Science Journal Classification (ASJC) codes

  • Cardiology and Cardiovascular Medicine

Cite this

Kusuki, H., Kuriki, M., Horio, K., Hosoi, M., Matsuura, H., Fujino, M., Eryu, Y., Miyata, M., Yasuda, T., Yamazaki, T., Nagaoka, S., & Hata, T. (2011). Beat-to-beat QT interval variability in children: Normal and physiologic data. Journal of Electrocardiology, 44(3), 326-329.