Effect of heart rate on the hemodynamics in healthy and stenosed carotid arteries

Abstract

Stenosis in the internal carotid arteries is a serious cardiovascular condition. It is well-reported that low and oscillatory wall shear stress enhances the risk of stenosis progression. However, the effects of increased heart rates in highly stenosed arteries are not well explored. A detailed understanding of the flow features and stress distribution in stenosed carotid arteries at different heart rates may help clinicians to prescribe better exercise schedules for patients. In this study, we probe the effects of elevated heart rates on the hemodynamics in healthy and stenosed carotid arterial geometries using an immersed boundary method-based computational framework. Our results reveal that a strong recirculation, secondary velocity, and oscillatory shear index (OSI) zone develop inside a severely stenosed carotid artery at normal heart rate. Higher heart rates may potentially improve arterial health by reducing OSI only for the healthy and mild stenosis carotid arteries. However, the increased heart rates worsen the arterial health of severely stenosed arteries by onsetting flow instabilities, enhancing the spread and severity of the recirculation zone and the magnitude of the secondary velocity, the pressure drops across the stenosis, and the spread of high OSI (≥0.2) zone downstream. Furthermore, in the case of severe stenosis, the wall shear stress at the stenosis throat rises significantly, which can contribute to plaque rupture and thrombus development. Here, we report in detail the behavior of stress levels and pressure fluctuations in the carotid artery model at different stenosis levels for normal and elevated heart rates.

Prediction of Hemodynamic-Related Hemolysis in Carotid Stenosis and Aiding in Treatment Planning and Risk Stratification Using Computational Fluid Dynamics

“…The information obtained thanks to imaging methods allowed for the visualization of stenoses and the creation of accurate CFD simulation models. CFD simulations can be a valuable tool in a wide range of blood flows in the circulatory system [10,27,[63][64][65][66][67][68][69][70][71][72][73], providing valuable information for physicians. CFD can provide information on high shear stress [10,[63][64][65], which is one of the factors causing blood hemolysis, which negatively affects patients' health [74].…”

Carotid Artery Digital Twin Based On Reduced-Order Model

“…To address the research gap, digital twins of both healthy carotid arteries and those with varying degrees of stenosis were constructed in this work. Specifically, computational fluid dynamics (CFD) simulations on carotid arteries exhibiting varying degrees of stenosis were conducted to procure hemodynamic results under various heart rates [3]. The reduced order model (ROM) Builder Pre module was employed to export the simulation results as training files, encompassing solely grid node coordinates and individual hemodynamic parameters (e.g., velocity, pressure, and wall shear stress) [4,5].…”