Electrophysiological characteristics of ventricular arrhythmias developed in hypothermic conditions.

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K08574
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 53020:Cardiology-related
• Research Institution: Niigata University
• Principal Investigator: Saitoh Osamu 新潟大学, 医歯学系, 講師 (40752457)
• Co-Investigator(Kenkyū-buntansha): 池主 雅臣 新潟大学, 医歯学系, 教授 (40303151)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 低体温 / 不整脈

Outline of Final Research Achievements

This study was performed to clarify hypothermia arrhythmias' electrophysiological and excitatory characteristics using the porcine heart model.
The main findings of this study were as follows; suppressed automaticity, slowed conduction, prolonged repolarization, more heterogeneous distribution of repolarization, higher pacing stimulus threshold and reduced cardiac contraction were observed as myocardial temperature decreased (37, 32, 28℃). In addition, ventricular arrhythmias were most frequently induced at 28 ℃ by programmed electrical stimulation. Ventricular fibrillation in advanced hypothermia was accompanied by an increased defibrillation threshold and decreased dominant frequency and power.
These results seemed to be characterized as therapy-resistant ventricular arrhythmias in the advanced hypothermic condition.

Free Research Field

循環器生理

Academic Significance and Societal Importance of the Research Achievements

雪山遭難、海難事故などで生じる低体温不整脈が治療抵抗性を示す機序を解明するため低体温環境を再現して基礎実験を行った。本研究では食用ブタ心臓モデルを用い、心電図指標および心室不整脈の周波数解析から①心筋温度低下に伴って形成される不整脈基盤の電気生理学的特徴、②心室不整脈の興奮特性（周波数、パワー値）を明らかにし、低体温で生じる心室細動が治療抵抗性を示す要因を見出した。これらの知見は重症低体温症例の救命と自立性の高い社会復帰の実現、低体温療法の安全性向上に貢献するものと考える。