1. Myocardial repolarization time, J-point to T-peak and T-peak to T-end intervals, have different heart rate dependency and autonomic nerve interference in healthy prepubertal children
- Author
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Kayo Horio, Hideaki Matsuura, Miki Nishio, Rina Nagata, Yuri Mizutani, Misa Hosoi, Yumi Kiriyanagi, Tadayoshi Hata, Hirofumi Kusuki, Shota Oikawa, Yuka Tsuchiya, and Tsuneaki Sadanaga
- Subjects
Male ,medicine.medical_specialty ,Heart disease ,RR interval ,030204 cardiovascular system & hematology ,Autonomic Nervous System ,Electrocardiography ,03 medical and health sciences ,0302 clinical medicine ,Heart Rate ,Internal medicine ,Heart rate ,medicine ,Humans ,Autonomic Pathways ,Spectral analysis ,030212 general & internal medicine ,Child ,Autonomic nerve ,Myocardial repolarization ,business.industry ,Myocardium ,Mean age ,medicine.disease ,Coherence analysis ,Child, Preschool ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,business - Abstract
The JT interval of the myocardial repolarization time can be divided into Jpoint to T-peak interval (JTp) and T-peak to T-end interval (Tpe). It is well known that the JT interval is dependent on the heart rate, but little is known regarding heart rate dependence for JTp and Tpe. The aim of the present study was to clarify the heart rate dependence of JTp and Tpe and to elucidate the interference of autonomic nervous activity with these parameters.We evaluated 50 prepubertal children (mean age: 6.4 ± 0.5 years; male:female, 22:28) without heart disease. JTp, Tpe, and the preceding RR intervals were measured using 120 consecutive beats (lead CM5). First, the relationships between the RR interval and JTp and Tpe were evaluated by Pearson's correlation coefficient. Second, to evaluate autonomic interference with JTp and Tpe, the degree of coherence between RR interval variability and JTp or Tpe variability was calculated using spectral analysis.Significant positive correlations were observed between the RR interval and JTp (y = 0.116x + 105.5; r = 0.594, p0.001) and between the RR interval and Tpe (y = 0.037x + 44.7; r = 0.432, p0.001). Tpe variability had a lower degree of coherence with RR interval variability (range: 0.039-0.5 Hz) than with JTp variability (0.401 [interquartile range, 0.352-0.460] vs. 0.593 [0.503-0.664], respectively; p0.001).Tpe had lower heart rate dependence and a lower degree of autonomic nervous interference than did JTp.
- Published
- 2021