Effects of transmural pressure and wall shear stress on LDL accumulation in the arterial wall: a numerical study using a multilayered model
| Autor: | Simon A. McG. Thom, Nanfeng Sun, Alun D. Hughes, Nigel B. Wood, X. Yun Xu |
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| Rok vydání: | 2007 |
| Předmět: |
medicine.medical_specialty
Materials science Physiology Flow (psychology) Blood Pressure Severity of Illness Index Stress (mechanics) Physiology (medical) Internal medicine medicine Shear stress Fluid dynamics Animals Humans Computer Simulation Mathematical model Coronary Stenosis Models Cardiovascular Mechanics Atherosclerosis Coronary Vessels Lipoproteins LDL Coupling (electronics) medicine.anatomical_structure Endocrinology Blood pressure Hypertension Stress Mechanical Cardiology and Cardiovascular Medicine Artery |
| Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 292:H3148-H3157 |
| ISSN: | 1522-1539 0363-6135 |
| DOI: | 10.1152/ajpheart.01281.2006 |
| Popis: | The accumulation of low-density lipoprotein (LDL) is recognized as one of the main contributors in atherogenesis. Mathematical models have been constructed to simulate mass transport in large arteries and the consequent lipid accumulation in the arterial wall. The objective of this study was to investigate the influences of wall shear stress and transmural pressure on LDL accumulation in the arterial wall by a multilayered, coupled lumen-wall model. The model employs the Navier-Stokes equations and Darcy's Law for fluid dynamics, convection-diffusion-reaction equations for mass balance, and Kedem-Katchalsky equations for interfacial coupling. To determine physiologically realistic model parameters, an optimization approach that searches optimal parameters based on experimental data was developed. Two sets of model parameters corresponding to different transmural pressures were found by the optimization approach using experimental data in the literature. Furthermore, a shear-dependent hydraulic conductivity relation reported previously was adopted. The integrated multilayered model was applied to an axisymmetric stenosis simulating an idealized, mildly stenosed coronary artery. The results show that low wall shear stress leads to focal LDL accumulation by weakening the convective clearance effect of transmural flow, whereas high transmural pressure, associated with hypertension, leads to global elevation of LDL concentration in the arterial wall by facilitating the passage of LDL through wall layers. |
| Databáze: | OpenAIRE |
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