Numerical Modeling of Intraventricular Flow during Diastole after Implantation of BMHV

Abstract

This work presents a numerical simulation of intraventricular flow after the implantation of a bileaflet mechanical heart valve at the mitral position. The left ventricle was simplified conceptually as a truncated prolate spheroid and its motion was prescribed based on that of a healthy subject. The rigid leaflet rotation was driven by the transmitral flow and hence the leaflet dynamics were solved using fluid-structure interaction approach. The simulation results showed that the bileaflet mechanical heart valve at the mitral position behaved similarly to that at the aortic position. Sudden area expansion near the aortic root initiated a clockwise anterior vortex, and the continuous injection of flow through the orifice resulted in further growth of the anterior vortex during diastole, which dominated the intraventricular flow. This flow feature is beneficial to preserving the flow momentum and redirecting the blood flow towards the aortic valve. To the best of our knowledge, this is the first attempt to numerically model intraventricular flow with the mechanical heart valve incorporated at the mitral position using a fluid-structure interaction approach. This study facilitates future patient-specific studies.

Application of Patient-Specific Computational Fluid Dynamics in Coronary and Intra-Cardiac Flow Simulations: Challenges and Opportunities

“…Figure 4 illustrates the general process of CFD simulation of blood flow in the LV based on cardiac MRI images (Su et al, 2015 ). Images comprise the long-axis and a stack of 12–14 short-axis images covering the LV from apex to base.…”

Fluid–Structure Interaction and In Vitro Analysis of a Real Bileaflet Mitral Prosthetic Valve to Gain Insight Into Doppler-Silent Thrombosis

“…First, the approaches used to impose FSI, either through moving methods, as for the Arbitrary Lagrangian Eulerian (ALE) method [6][7][8][9][10], or through fixed grid methods consisting in evolutions of the Immersed Boundary (IB) method [11][12][13]. Second, the site of simulated BMV implantation, which is the aortic position in the vast majority of the published studies [7,8,[14][15][16][17], and is the mitral position only in few studies [18]. Third, the aim of the numerical analysis, which can range to the highly detailed quantification of shear stresses exerted on blood flowing through the valve as a mean to assess the risk of mechanically induced blood damage [16] to the assessment of intraventricular fluid dynamics associated to the presence of a BMV either in aortic [19] or mitral [18] position.…”

Computational fluid dynamics simulation of blood flow profile and shear stresses in bileaflet mechanical heart valve by using monolithic approach

“…Since the plasma has properties of Newtonian fluid (the shear rate is linear), this assumption is considered valid. 14,15,16 The body forces are neglected due to the short computational domain of 130 mm.…”

“…A large amount of work has been performed, but one of the main challenges in BMHV simulation remains, which is the interaction between valve leaflets and blood flow. 14,15 In order to simulate this interaction, mesh grid should be developed. There are two approaches in developing this mesh which are partitioned and monolithic.…”