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Scaling laws for wall shear stress through stenoses under steady and pulsatile flow conditions
1Thermal and Fluids Engineering Division, School of Mechanical and Production Engineering, Nanyang Technological University, Singapore.
Insights
This study introduces a method to normalize wall shear stresses in coronary artery stenosis under various flow conditions. The findings simplify complex flow dynamics, aiding in understanding atherosclerosis progression and plaque rupture.
Area of Science:
- Cardiovascular fluid dynamics
- Biomedical engineering
- Medical imaging analysis
Background:
- Atherosclerosis commonly involves epicardial coronary artery stenoses.
- Wall shear stress in high-grade stenoses is critical for understanding plaque rupture and thrombosis.
- Current methods lack a unified approach to analyze wall shear stress across diverse flow conditions.
Purpose of the Study:
- To develop a scalable method for normalizing wall shear stress (WSS) in coronary artery stenoses.
- To create a general curve for collapsed WSS data under different flow conditions.
- To investigate WSS scaling laws for both steady and pulsatile flow.
Main Methods:
- Computational fluid dynamics (CFD) simulations were performed.
- Simulations included steady and pulsatile flow models.
- Stenoses with reduced area percentages of 50%, 75%, and 90% were analyzed.
Main Results:
- Proposed scaling laws for steady and pulsatile flow conditions.
- Demonstrated normalization and collapsing of WSS data onto a general curve.
- Identified that pulsatile flow WSS scaling is more complex than steady flow.
Conclusions:
- A novel method for normalizing WSS in coronary stenoses was established.
- The study provides insights into the biomechanics of atherosclerosis.
- Pulsatile flow analysis requires consideration of specific time intervals for accurate scaling.
Abstract:
Most patients with atherosclerosis exhibit isolated stenoses of one or more epicardial coronary arteries. The wall shear stresses produced in high-grade stenosis are important in the understanding of atheromatous plaque rupture and thrombosis. This study is designed to establish a method which can be used to scale the different wall shear stresses obtained under different flow conditions to be normalized and subsequently collapsed on to a single general curve. The simulations include both steady and pulsatile flow. The reduced area percentages of the stenoses studied are 50, 75 and 90 per cent. Scaling laws for steady and pulsatile flow conditions are proposed and presented. It can be found from the results that the scaling analysis for pulsatile flow conditions is more complicated than for steady flow conditions and is restricted to, and only valid at, certain time intervals.