Modeling the role of the coronary vasculature during external field stimulation.
Modeling the role of the coronary vasculature during external field stimulation.
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DOI：
10.1109/tbme.2010.2051227
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发表时间：
2010-10
期刊：
影响因子：
--
通讯作者：
Vigmond EJ
中科院分区：
文献类型：
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作者：
Bishop MJ;Boyle PM;Plank G;Welsh DG;Vigmond EJ
除颤电击刺激远离电极和心脏表面的心脏组织的确切机制需要阐明。双域理论通过心肌组织结构不连续性引起的壁内虚拟电极（VEs）的存在来解释这一现象。在这项研究中，我们从高分辨率MR数据中评估了构建包括血管在内的有限元心脏组织模型所必需的建模组件，并研究了冠状动脉血管在VE形成中的具体作用，这在很大程度上仍然是未知的。我们使用了一种新的方法来分配基于组织学的纤维结构，并在模型中包括实验衍生的血管管腔壁电导。通过与缺乏内部结构的简化模型进行比较，评估了存在血管的冲击组织相互作用。结果表明，在震荡时，血管周围会形成VEs，电压为8v /cm。诱导极化的大小通过血管腔周围的纤维协商以及血管管腔壁的绝缘效应的真实表现而衰减。此外，在大的心外膜下血管周围形成的VEs降低了心外膜的极化水平。总之，我们发现冠状动脉血管是VE形成的重要底物，这可能有助于解释光学制图数据。
The exact mechanisms by which defibrillation shocks excite cardiac tissue far from both the electrodes and heart surfaces require elucidation. Bidomain theory explains this phenomena through the existence of intramural virtual electrodes (VEs), caused by discontinuities in myocardial tissue structure. In this study, we assess the modelling components essential in constructing a finite element cardiac tissue model including blood vessels from high resolution MR data and investigate the specific role played by coronary vasculature in VE formation, which currently remains largely unknown. We use a novel method for assigning histologically-based fibre architecture around intramural structures and include an experimentally-derived vessel lumen wall conductance within the model. Shock-tissue interaction in the presence of vessels was assessed through comparison with a simplified model lacking intramural structures. Results indicate that VEs form around blood vessels for shocks > 8 V/cm. The magnitude of induced polarisations is attenuated by realistic representation of fibre negotiation around vessel cavities, as well as the insulating effects of the vessel lumen wall. Furthermore, VEs formed around large sub-epicardial vessels reduce epicardial polarisation levels. In conclusion, we have found that coronary vasculature acts as an important substrate for VE formation, which may help interpretation of optical mapping data.