Integrative model of coronary flow in anatomically based vasculature under myogenic, shear, and metabolic regulation.
Integrative model of coronary flow in anatomically based vasculature under myogenic, shear, and metabolic regulation.
复制标题
在肌源性、剪切力和代谢调节下基于解剖学的脉管系统中冠状动脉血流的综合模型。
DOI：
10.1085/jgp.201711795
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Lanir,Yoram
中科院分区：
文献类型：
--
作者：
Namani,Ravi;Kassab,GhassanS;Lanir,Yoram
调节冠状动脉血流以匹配心脏壁中的肌细胞的氧需求。流量调节对于满足广泛的心脏工作负荷是必不可少的。在透壁异质性心肌血管外负荷下，血液流过具有非线性壁特性的弹性血管的复杂冠状血管系统。到目前为止，还没有一个完全综合的流量分析，包括全球和当地的被动和流量控制的决定因素。在这里，我们提供了一个综合模型的冠状动脉流量调节，考虑现实的不对称形态的冠状动脉网络，动态心肌负荷的血管嵌入其中，并结合局部生肌效应，局部剪切调节，并进行代谢控制驱动的静脉O2饱和度水平。该模型预测自动调节（在宽范围的冠状动脉灌注压近似恒定的流量），减少异质性的调节流量，并存在流量储备，与实验观察结果一致。此外，该模型表明，代谢和生肌调节发挥了主要作用，而剪切有一个次要的。调节被发现有一个显着的影响，除了在极端（高和低）的入口压力和代谢的需求。该模型的新结果是，冠状动脉血管上的周期性心肌负荷增强了冠状动脉血流储备（低入口灌注压除外），增加了有效自动调节的压力范围，并在缺乏代谢调节的情况下减少了网络流量。总的来说，这些发现证明了本生物物理模型的实用性，它可以用来解开冠状动脉病理生理学的潜在机制。
Coronary blood flow is regulated to match the oxygen demand of myocytes in the heart wall. Flow regulation is essential to meet the wide range of cardiac workload. The blood flows through a complex coronary vasculature of elastic vessels having nonlinear wall properties, under transmural heterogeneous myocardial extravascular loading. To date, there is no fully integrative flow analysis that incorporates global and local passive and flow control determinants. Here, we provide an integrative model of coronary flow regulation that considers the realistic asymmetric morphology of the coronary network, the dynamic myocardial loading on the vessels embedded in it, and the combined effects of local myogenic effect, local shear regulation, and conducted metabolic control driven by venous O2saturation level. The model predicts autoregulation (approximately constant flow over a wide range of coronary perfusion pressures), reduced heterogeneity of regulated flow, and presence of flow reserve, in agreement with experimental observations. Furthermore, the model shows that the metabolic and myogenic regulations play a primary role, whereas shear has a secondary one. Regulation was found to have a significant effect on the flow except under extreme (high and low) inlet pressures and metabolic demand. Novel outcomes of the model are that cyclic myocardial loading on coronary vessels enhances the coronary flow reserve except under low inlet perfusion pressure, increases the pressure range of effective autoregulation, and reduces the network flow in the absence of metabolic regulation. Collectively, these findings demonstrate the utility of the present biophysical model, which can be used to unravel the underlying mechanisms of coronary physiopathology.