Functional assessment after cardiac surgery using inert gas rebreathing method

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K10220
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Cardiovascular surgery
• Research Institution: Gifu University (2018); Kyoto Prefectural University of Medicine (2015-2017)
• Principal Investigator: Doi Kiyoshi 岐阜大学, 大学院医学系研究科, 教授 (40305579)
• Research Collaborator: Yamano Tetsuhiro ; Shiraishi Hirokazu ; Yamazaki Sachiko ; Yaku Hitoshi
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 運動負荷試験 / 僧帽弁形成術 / 機能性僧帽弁狭窄 / 心臓超音波検査 / 不活性ガス再呼吸法

Outline of Final Research Achievements

Annuloplasty ring size determines the exercise-induced mitral stenosis severity after mitral valve repair. In this study, cardiac output during exercise was measured by use of inert gas rebreathing method and echocardiography after mitral valve repair.
Cardiac output of patients during peak exercise was significantly lower than that of normal controls. Cardiac output during peak exercise of patients were almost constant regardless of the size of the annuloplasty ring used. As long as the patients are almost asymptomatic, their cardiac output reasonably increase during exercise even if they have significant mitral valve stenosis.

Free Research Field

心臓血管外科

Academic Significance and Societal Importance of the Research Achievements

僧帽弁形成術後の運動負荷誘発性狭窄症の臨床的意義についてこれまで議論されてきた。本研究は心機能が良好な患者であれば、高度狭窄が存在しても運動中の心拍出量を維持出来ることを示した。しかしながら狭窄症を有する患者では、同じ心拍出量を確保するための心筋エネルギー消費量は大きくなるため、低心機能患者では問題となると予測される。今後はMRI流体解析などによるエネルギー損失の評価を研究に導入する予定である。