Radiofrequency ablation of ventricular arrhythmias arising from deep myocardium (coronary perfused beating hearts in the dual-bath experimental setting)

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K08512
• 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: Chinushi Masaomi 新潟大学, 医歯学系, 教授 (40303151)
• Co-Investigator(Kenkyū-buntansha): 齋藤 修 新潟大学, 医歯学系, 講師 (40752457)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 高周波アブレーション / 不整脈

Outline of Final Research Achievements

Using an experimental model of porcine myocardium that beat and contract with coronary perfusion, we constructed an experimental system in which radiofrequency ablation can be performed while monitoring myocardial excitation (local potential, excitation threshold and electrocardiogram), delivering electrical parameters (current, voltage, and impedance), and ultrasound imaging information.
The following approaches were considered effective in improving ablation efficiency; (1) use of the Bipolar ablation method, and (2) appropriately long application time for maximizing the conduction heating effect. Short-time application using irrigation catheter may restore the excitation of superficial myocardium. Important items to ensure safety were as follows; (1) avoid high power energy delivered by Bipolar ablation method for thin myocardial areas to prevent steam-pop, and (2) limit total impedance drop during ablation within 20-25 ohm

Free Research Field

循環器内科

Academic Significance and Societal Importance of the Research Achievements

医用工学の進歩によって不整脈起源の局在を視覚同定することが可能となったが、心筋表層起源とは異なり、深部心筋起源を安定焼灼する治療技術の開発は大きく遅れている。しかし心臓突然死の主要原因である重症心室不整脈（心室細動・心室頻拍）は深部心筋起源の場合が多く、現在も難治症例を多く経験する。今回の課題は臨床例の高周波アブレーション治療を模倣した実験環境を構築して行い、心筋焼灼に関わる複数因子を網羅的に設定して有効性と安全性に優れた通電条件を検証した。深部起源の重症不整脈の治療は、救命、自立した社会復帰、医療経済などの複数観点から重要かつ有益で、医療現場と地域社会の要求に合致した成果と考えている。