Open Access

ARTICLE

Hemodynamics of Enhanced External Counterpulsation with Different Coronary Stenosis

Sihan Chen¹, Bao Li¹, Haisheng Yang¹, Jianhang Du², Xiaoling Li², Youjun Liu^1,*

1 College of Life Science and Bio-engineering, Beijing University of Technology, No. 100 Ping-leyuan, Chaoyang District, Beijing, 100124, China.
2 The Eighth Affiliated Hospital, Sun Yat-sen University, No. 3025 ShenNan Road, ShenZhen, GuangDong, 518033, China.

*Corresponding Author: Youjun Liu. Email: .

(This article belongs to this Special Issue: Innovations and Current Trends in Computational Cardiovascular Modeling: Molecular, Cellular, Tissue and Organ Biomechanics with Clinical Applications)

Computer Modeling in Engineering & Sciences 2018, 116(2), 149-162. https://doi.org/ 10.31614/cmes.2018.04133

Abstract

Enhanced external counterpulsation (EECP) is able to treat myocardial ischemia, which is usually caused by coronary artery stenosis. However, the underlying mechanisms regarding why this technique is effective in treating myocardial ischemia remains unclear and there is no patient-specific counterpulsation mode for different rates of coronary artery stenosis in clinic. This study sought to investigate the hemodynamic effect of varied coronary artery stenosis rates when using EECP and the necessity of adopting targeted counterpulsation mode to consider different rates of coronary artery stenosis. Three 3-dimensional (3D) coronary models with different stenosis rates, including 55% (Model 1), 65% (Model 2), and 75% (Model 3), were generated, then coupled with a 0-dimensional (0D) lumped parametric model of the blood circulatory system. EECP was applied to the 0D/3D coupled models to study the hemodynamic response of the coronary artery. Under the same counterpulsation mode, the ratio of diastolic blood pressure to systolic blood pressure of 3 models during counterpulsation was 1.4, and the cardiac output and coronary artery flow rate increased significantly. The low wall shear stress (WSS) and high oscillatory shear index (OSI) areas were mainly located at the posterior end of the stenosis and coronary artery bifurcation. Moreover, with an increase in the rate of coronary artery stenosis, the increased percentage of flow rate through the coronary artery stenosis and area-averaged WSS decreased. The geometric multiscale model in this study can be used to effectively simulate the hemodynamic characteristics of cardiovascular system following the application of EECP. Local precise hemodynamic effect of the coronary artery stenosis can be observed. It was found from the hemodynamic factors that the coronary artery with lower stenosis rate more likely led to better vascular endothelial remodeling. Thus, it is necessary to adopt patient-specific counterpulsation mode accounting for different condition of coronary artery stenosis.

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