Myocardial repolarization variability index indicates healthy development in children

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K02505
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 09030:Childhood and nursery/pre-school education-related
• Research Institution: Fujita Health University
• Principal Investigator: Hata Tadayoshi 藤田医科大学, ばんたね病院 臨床検査部, 病院特命教授 (70267954)
• Co-Investigator(Kenkyū-buntansha): 宮田 昌史 藤田医科大学, 医学部, 教授 (00387721)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 小児科学 / 心筋再分極 / 自律神経活動 / 心拍変動 / QT時間 / T peak to T end interval / QT variability index / 低体温療法

Outline of Final Research Achievements

[Description] Hypothermia-induced myocardial repolarization abnormalities in neonates are largely unknown. Therefore, we analyzed the electrocardiogram and examined the effect on depolarization/repolarization. The subjects were neonates with hypoxic-ischemic encephalopathy who underwent therapeutic cerebral hypothermia. HR, RR, P wave, PR, QRS, QT, QTc, JT, JTc, Tp-e, Tp-e/QT, and QRS/QTc were calculated from the electrocardiogram.
[Results] QTc and JTc showed a significant negative correlation with hypothermia, and Tp-e/QT and QRS/QT showed a significant positive correlation with hypothermia.
[Directions] Therapeutic hypothermia did not affect the myocardial depolarization process in premature neonates, prolonging the repolarization process but negatively proarrhythmic exacerbation.

Free Research Field

心臓電気生理学・心電図学

Academic Significance and Societal Importance of the Research Achievements

小児期の自律神経の発達は心電図より算出する心拍変動の分析値に反映される事が知られている。我々は先行研究として心筋再分極異常を検出できるQT variability indexおよびTp-e/QTは心拍変動と強い相関性を有すること、さらに生後1ヶ月児では在胎週数に相関した自律神経機能の成熟度を心筋再分極指標から推測できる事を示した。さらに今回報告した治療的低体温が新生児の未熟な心筋脱分極・再分極に与える影響を初めて提示した報告であり、今後の新生児医療、中でも乳幼児突然死症候群の予防に応用される情報と考える。