2019 Fiscal Year Final Research Report

Potential Mechanism of Left Ventricular Spherical Remodeling: Association of Mitral Valve Complex-Myocardium Longitudinal Tissue Remodeling Mismatch

Research Project

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Project/Area Number	17K09538
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Cardiovascular medicine
Research Institution	University of Occupational and Environmental Health, Japan
Principal Investigator	Otsuji Yutaka 産業医科大学, 医学部, 教授 (30264427)
Co-Investigator(Kenkyū-buntansha)	荻ノ沢泰司産業医科大学, 医学部, 助教 (20596720) 竹内正明産業医科大学, 大学病院, 准教授 (30236434) 宮本哲産業医科大学, 大学病院, 准教授 (30611305) 岩瀧麻衣産業医科大学, 医学部, 助教 (40771308) 西村陽介産業医科大学, 医学部, 教授 (50301338) 尾上武志産業医科大学, 医学部, 非常勤医師 (50772703) 永田泰史産業医科大学, 医学部, 非常勤医師 (60749993) 園田信成産業医科大学, 医学部, 准教授 (90299610)
Project Period (FY)	2017-04-01 – 2020-03-31
Keywords	心不全 / 僧帽弁 / 心エコー図
Outline of Final Research Achievements	Mitral valve complex (MVC) longitudinal tissue length (LL) less elongation vs. whole left ventricular (LV) myocardial LL elongation may limit LV-base-LL elongation, leading to LV spherical remodeling. In 30 patients with dilated cardiomyopathy (DCM), 30 with aortic regurgitation, and 30 controls, LV sphericity, LV-apex-transverse tissue length (TL) and -LL, LV-base-TL and -LL, MVC-LL and whole-LV-LL were measured by 3D echo. Ratio of each measure vs. mean normal value was obtained. LV-apex-TL, LV-apex-LL and LV-base-TL ratios were increased (p<0.01), while the LV-base-LL ratio was not increased in DCM. Whole-LV-LL ratio was increased (p<0.01), while MVC-LL ratio was not increased in DCM. Multivariable analysis revealed that LV sphericity was related to a reduced [LV-base-LL ratio/global-LV ratio] (p<0.01), which was related to a reduced [MVC-LL ratio/whole-LV-LL ratio] (p<0.01). Less MVC-LL elongation vs. whole LV myocardial tissue elongation may contribute to LV spherical remodeling.
Free Research Field	循環器内科
Academic Significance and Societal Importance of the Research Achievements	心不全（心臓機能異常による息切れ等）では、なぜか楕円形の心臓筋肉が球形に近くなります。球形化は心機能を保つ上で不利とされていますが、「なぜ心臓筋肉が球形化するか？」は不明です。本研究では、「心臓の筋肉全体が伸びる（拡大）する中で心臓筋肉基部を縦につなぐ僧帽弁複合体組織があまり伸びないのでそこの心臓筋肉が縦に伸びれないために心臓全体が球形化する」という仮説を検討し、この仮説を裏付けるデータを出しました。「僧帽弁複合体組織があまり伸びない」ために「心臓筋肉が球形化する」という概念もデータも初めてです。