Effect of pulmonary regurgitation on cardiac functions based on a human bi-ventricle model

Yin, X. and Wang, Y. (2023) Effect of pulmonary regurgitation on cardiac functions based on a human bi-ventricle model. Computer Methods and Programs in Biomedicine, 238, 107600. (doi: 10.1016/j.cmpb.2023.107600) (PMID:37285726)

Abstract

Background and objective: Assessing the severity of pulmonary regurgitation (PR) and identifying optimal clinically relevant indicators for its treatment is crucial, yet standards for quantifying PR remain unclear in clinical practice. Computational modelling of the heart is in the process of providing valuable insights and information for cardiovascular physiology research. However, the advancements of finite element computational models have not been widely applied to simulate cardiac outputs in patients with PR. Furthermore, a computational model that incorporates both the left ventricle (LV) and right ventricle (RV) can be valuable in assessing the relationship between left and right ventricular morphometry and septal motion in PR patients. To enhance our understanding of the effect of PR on cardiac functions and mechanical behaviour, we developed a human bi-ventricle model to simulate five cases with varying degrees of PR severity. Methods: This bi-ventricle model was built using a patient-specific geometry and a widely used myofibre architecture. The myocardial material properties were described by a hyperelastic passive constitutive law and a modified time-varying elastance active tension model. To simulate realistic cardiac functions and the dysfunction of the pulmonary valve in PR disease cases, open-loop lumped parameter models representing systemic and pulmonary circulatory systems were designed. Results: In the baseline case, pressures in the aorta and main pulmonary artery and ejection fractions of both the LV and RV were within normal physiological ranges reported in the literature. The end-diastolic volume (EDV) of the RV under varying degrees of PR was comparable to the reported cardiac magnetic resonance imaging data. Moreover, RV dilation and interventricular septum motion from the baseline to the severe cases were clearly observed through the long-axis and short-axis views of the bi-ventricle geometry. The RV EDV in the severe PR case increased by 50.3% compared to the baseline case, while the LV EDV decreased by 18.1%. The motion of the interventricular septum was consistent with the literature. Furthermore, ejection fractions of both the LV and RV decreased as PR became severe, with LV ejection fraction decreasing from 60.5% at baseline to 56.3% in the severe case and RV ejection fraction decreasing from 51.8% to 46.8%. Additionally, the average myofibre stress of the RV wall at end-diastole significantly increased due to PR, from 2.7±12.1 kPa at baseline to 10.9±26.5 kPa in the severe case. The average myofibre stress of the LV wall at end-diastole increased from 3.7±18.1 kPa to 4.3±20.3 kPa. Conclusions: This study established a foundation for the computational modelling of PR. The simulated results showed that severe PR leads to reduced cardiac outputs in both the LV and RV, clearly observable septum motion, and a significant increase in the average myofibre stress in the RV wall. These findings demonstrate the potential of the model for further exploration of PR.

• Item Type: Articles
• Additional Information: Y. Wang acknowledges funding from the Chinese Scholarship Council and the fee waiver from the University of Glasgow.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Wang, Yingjie and Yin, Ms Xueqing
• Authors: Yin, X., and Wang, Y.
• College/School: College of Science and Engineering > School of Mathematics and Statistics
• Journal Name: Computer Methods and Programs in Biomedicine
• Publisher: Elsevier
• ISSN: 0169-2607
• ISSN (Online): 1872-7565
• Published Online: 19 May 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Computer Methods and Programs in Biomedicine 238:107600
• Publisher Policy: Reproduced under a Creative Commons license