Document Type : Research Article
Department of Mechanical Engineering, Faculty of Engineering, Kermanshah, Iran
Energy Research Center, Amirkabir University of Technology, Tehran, Iran
This work studies the effect of cardiac function parameters on ventricular flow pattern in a stenosed mitral. A three-dimensional simulation is performed employing dynamic mesh based on a geometry and valve flow rates extracted from medical images. Different mitral areas from 6 to 2 cm2 then different parameters for stenosed 2-cm2 case are investigated. Special attention has been drawn to compare wall shear stress, blood velocity and pressure distribution, while the power used by ventricle and atrium to pump the blood are also highlighted. Computing the power used by the heart walls to move the blood shows that the stenosed mitral increases the needed force and the energy for the blood flow suction during the early diastole (from 0.06 W for mitral area of 6 cm2 to 1.28 W for mitral area of 2 cm2). For the stenosed mitral area of 2 cm2, in the systole, decreasing the ejection fraction to half decreased the maximum ventricle power to around half. In the diastole, decreasing the E/A which is the ratio of early diastole (E wave) and late diastole (A wave) ratio from 4.8 to 1 decreased the maximum ventricle power to one-third. The numerical results confirmed that the compensation mechanism to afford the pumping power could be changing of the E/A ratio which leads to enlarged atrium.