Precise Fluid-Solid Simulation of Human Left Ventricle along with Aortic Valve during Systole

Abstract

This paper presents an accurate blood flow model with tissue deformation of the human left ventricle, including the aortic valve. A two-way fluid-solid Interaction (FSI) algorithm is employed to simulate the performance of the human left ventricle during systole. The initial geometry of the left ventricle is extracted from CT scan images of a healthy person. The simulation results produced the systolic anterior motion of the Left Ventricle (LV) identical with the CT scan images at later times during systole. Besides, the numerical results for left ventricular volume change, maximum blood velocity at the aortic valve, and its maximum opening are in good agreement with physiological data. Although no clear image of the aortic valve is apparent in CT images, the FSI simulation predicted the maximum opening of the aortic valve to be 4.38 cm2 which is consistent with physiological observation on a healthy individual. As an application of the above algorithm, a model of Hypertrophic Cardiomyopathy (HCM) or septal wall thickening disease is constructed and studied during systole. This simulation provides an understanding of heart performance under HCM conditions. According to the simulation outcomes, the mitral valve approaches the septal wall under HCM due to the change in pressure gradient and the drag force on the mitral valve. This blockage of the LV blood passage by the mitral valve results in stagnation pressure loss and weaker hearth pumping power. Therefore, the maximum opening of the aortic valve, in this case, is 2.28 cm2, which is much lower than the physiological range, indicating the drastic effect of HCM on the performance of the aortic valve and systolic performance.