Aging becomes a serious problem worldwide because of the progress of medical technology as well as social welfare. In human cardiovascular systems, histological changes in the structure of the blood vessels are progressed by aging and the elasticity of the vessels is decreased in elderly persons. Elevation of the aortic and the left ventricular pressure caused by the change of arterial vessels produces a great number of cardiovascular disease. In this study, the authors examined hemodynamic changes in their originally-developed mechanical circulatory system, in which the polyester vascular graft was installed in the ascending aortic portion. As a result, it was indicated that the increase of the arterial impedance caused by the vascular graft implantation might be elevate the hemodynamic load to the left ventricle of the patient.