School of Mathematics and Statistics, University of Glasgow, Glasgow, United Kingdom.
School of Mathematics and Statistics, University of Glasgow, Glasgow, United Kingdom.
Comput Methods Programs Biomed. 2024 Jan;243:107928. doi: 10.1016/j.cmpb.2023.107928. Epub 2023 Nov 21.
There is an increasing demand to establish integrated computational models that facilitate the exploration of coronary circulation in physiological and pathological contexts, particularly concerning interactions between coronary flow dynamics and myocardial motion. The field of cardiology has also demonstrated a trend toward personalised medicine, where these integrated models can be instrumental in integrating patient-specific data to improve therapeutic outcomes. Notably, incorporating a structured-tree model into such integrated models is currently absent in the literature, which presents a promising prospect. Thus, the goal here is to develop a novel computational framework that combines a 1D structured-tree model of coronary flow in human coronary vasculature with a 3D left ventricle model utilising a hyperelastic constitutive law, enabling the physiologically accurate simulation of coronary flow dynamics.
We adopted detailed geometric information from previous studies of both coronary vasculature and left ventricle to construct the coronary flow model and the left ventricle model. The structured-tree model for coronary flow was expanded to encompass the effect of time-varying intramyocardial pressure on intramyocardial blood vessels. Simultaneously, the left ventricle model served as a robust foundation for the calculation of intramyocardial pressure and subsequent quantitative evaluation of myocardial perfusion. A one-way coupling framework between the two models was established to enable the evaluation and examination of coronary flow dynamics and myocardial perfusion.
Our predicted coronary flow waveforms aligned well with published experimental data. Our model precisely captured the phasic pattern of coronary flow, including impeded or even reversed flow during systole. Moreover, our assessment of coronary flow, considering both globally and regionally averaged intramyocardial pressure, demonstrated that elevated intramyocardial pressure corresponds to increased impeding effects on coronary flow. Furthermore, myocardial blood flow simulated from our model was comparable with MRI perfusion data at rest, showcasing the capability of our model to predict myocardial perfusion.
The integrated model introduced in this study presents a novel approach to achieving physiologically accurate simulations of coronary flow and myocardial perfusion. It holds promise for its clinical applicability in diagnosing insufficient myocardial perfusion.
在生理和病理环境下探索冠状动脉循环，特别是研究冠状动脉血流动力学与心肌运动之间的相互作用，对建立集成计算模型的需求日益增长。心脏病学领域也呈现出向个体化医学发展的趋势，在这种趋势下，这些集成模型可以通过整合患者特定数据来提高治疗效果。值得注意的是，目前文献中缺乏将结构树模型纳入此类集成模型的方法，这是一个很有前景的研究方向。因此，本研究旨在开发一种新的计算框架，该框架将人体冠状动脉血管的一维结构树模型与利用超弹性本构定律的三维左心室模型相结合，实现对冠状动脉血流动力学的生理精确模拟。
我们采用了冠状动脉血管和左心室的先前研究中的详细几何信息来构建冠状动脉血流模型和左心室模型。结构树冠状动脉血流模型扩展到包含时变心肌内压力对心肌内血管的影响。同时，左心室模型为计算心肌内压力和随后对心肌灌注进行定量评估提供了坚实的基础。两个模型之间建立了单向耦合框架，以评估和检查冠状动脉血流动力学和心肌灌注。
我们预测的冠状动脉血流波形与已发表的实验数据吻合良好。我们的模型精确地捕捉到了冠状动脉血流的时相模式，包括收缩期出现的阻塞甚至反流。此外，我们对冠状动脉血流的评估考虑了全局和局部平均心肌内压力，结果表明，心肌内压力升高对应于对冠状动脉血流的阻塞作用增强。此外，我们的模型模拟的心肌血流与休息时的 MRI 灌注数据相当，展示了我们的模型预测心肌灌注的能力。
本研究提出的集成模型为实现冠状动脉血流和心肌灌注的生理精确模拟提供了一种新方法。它在诊断心肌灌注不足的临床应用方面具有很大的应用前景。
