The effect of pulse frequency and amplitude on hemodynamics in the carotid artery bifurcation

Background: The hemodynamics of a carotid artery bifurcation has been extensively investigated due to its importance in atherosclerosis and stroke occurrence. Most of the previous studies have examined changes in frequency and amplitude together, thereby overlooking the distinct effect of each of parameter. However, the heart pulse rate and amplitude are not always constant and increase during physical activity or cardiovascular exercises. Therefore, the variation in the pulse rate and the amplitude may cause a change in the hemodynamics and distinct effect of each needs to be understood.Methods: In this work, we study computationally the hemodynamics in a realistic carotid artery bifurcation for three different pulse rates and three different amplitudes assuming blood to be a shear-thinning fluid. At the outlet, a resistance boundary condition taking into account the effect of flow resistance caused by the downstream vessels is applied. Results: It is observed that with an increase in the frequency and the amplitude, the reverse flow near the bifurcation decreases, which leads to an increase in the time-averaged wall shear stress (TAWSS). Similarly, the higher frequency causes a decrease in the oscillatory shear index (OSI) and relative residence time (RRT). Further, the effect of downstream resistance on hemodynamic parameters is also assessed.Conclusions: The present work suggests that the higher pulse frequency and amplitude are helpful in reducing the chances of plaque formation corroborating the importance of physical activity in reducing the risk of atherosclerosis.