Elevated heart rates reduced oscillatory shear index in healthy and mild stenosis models but worsened hemodynamics in severe stenosis by increasing flow instabilities and wall shear stress.
Does elevated heart rate affect hemodynamics differently in healthy versus stenosed carotid arteries?
Elevated heart rates may improve hemodynamics in healthy or mildly stenosed carotid arteries but exacerbate adverse hemodynamic forces in severe stenosis, potentially increasing the risk of plaque rupture.
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.
Khan et al. (Thu,) conducted a other in Stenosis in the internal carotid arteries. Elevated heart rates vs. Normal heart rates was evaluated on Hemodynamics (oscillatory shear index, wall shear stress, pressure drops). Elevated heart rates reduced oscillatory shear index in healthy and mild stenosis models but worsened hemodynamics in severe stenosis by increasing flow instabilities and wall shear stress.