杉村 公史郎¹, 金井 浩¹, 中鉢 憲賢^{1, 2}, 塚原 保夫^{1, 3}, 小岩 喜郎^{1, 4}, 鎌田 英一^{1, 4}, 手塚 文明^{1, 5}

Kohshiro SUGIMURA¹, Hiroshi KANAI¹, Noriyoshi CHUBACHI^{1, 2}, Yasuo TSUKAHARA^{1, 3}, Yoshiro KOIWA^{1, 4}, Hideichi KAMADA^{1, 4}, Fumiaki TEZUKA^{1, 5}

¹東北大学大学院工学研究科電気・通信工学専攻, ²東北学院大学工学部電気工学科, ³東北大学大学院情報科学研究科, ⁴東北大学医学部第一内科, ⁵国立仙台病院臨床研究部

¹Department of Electrical Engineering Graduate School of Engineering, Tohoku University, ²Department of Electrical Engineering Faculty of Engineering, Tohoku Gakuin University, ³Graduate School of Information Sciences Tohoku University, ⁴First Department of Internal Medicine Tohoku University School of Medicine, ⁵Department of Pathology Sendai National Hospital Medical Research Division

キーワード : Doxorubicin cardiomyopathy, Heart wall vibration, Local myocardial thickening, Phased tracking, Ultrasonic transcutaneous measurement

In order to diagnose heart disease, we have developed a method for transcutaneously measuring and analyzing small velocity signals of the heart wall using ultrasound and conducted experiments in vivo clearly showing differences between results obtained from healthy human subjects and those obtained from patients with serious cases of doxorubicin cardiomyopathy. It is necessary to investigate the relationship between the above results obtained by noninvasive measurement and the pathological findings from actual myocardial tissue. Because it is highly invasive and imposes a high load, however, repeated biopsy in human patients is difficult. In this study, therefore, small velocity signals on both sides of the interventricular septum (IVS) were measured noninvasively, and change in thickness of the IVS during one cardiac cycle was evaluated for healthy rabbits (controls) (n=5) and rabbits with drug-induced cardiomyopathy after administration of anthracycline carcinostatic for periods of about 5 (n=3) and 10 weeks (n=2). The experimental results confirmed that average ratio of maximum change in thickness of the IVS during one cardiac cycle to thickness at the time of R-wave (ECG) decreased from 1/4 for controls to 1/8 for those medicated for about 10-weeks as total dose of anthracycline carcinostatic was increased. On the other hand, average percent damage of myocardial tissue in the IVS increased from 0.1% in the controls to 38.7% for the 10-week group. We therefore conclude that there is clear a relationship between measurement results obtained using ultrasound and the pathological findings.