Activation dynamics in anisotropic cardiac tissue via decoupling
Activation dynamics in anisotropic cardiac tissue via decoupling
复制标题
DOI：
10.1023/b:abme.0000032461.80932.eb
复制
发表时间：
2004-07-01
影响因子：
3.8
通讯作者：
Horácek, BM
中科院分区：
文献类型：
--
作者：
Clements, JC;Nenonen, J;Horácek, BM
心脏组织的Bidomain理论假设两种互穿各向异性介质-细胞内（i）和细胞外（e）-通过细胞膜到处连接;四个局部参数σ（l，t）（i，e）指定相对于心肌纤维的纵向（l）和横向（t）方向的电导率。电激活传播的完整bidomain模型由跨膜电位v（m）和细胞外电位phi（e）的耦合椭圆-抛物偏微分方程以及心外区域电流流动的准静态方程组成。在这项工作中，我们开发了一个初步评估的后果，忽略了影响的被动心外组织和心内血液质量波传播孤立的整个心脏模型，并描述了一个解耦的过程，它不需要假设的各向异性的电导率，并产生一个单一的反应扩散方程模拟激活的传播。根据无量纲参数Σ =（sigma（l）（i）sigma（t）（e）- sigma（t）（i）sigma（l）（e））/（sigma（l）（i）+ sigma（l）（e））（sigma（t）（i）+ sigma（t）（e）），证明了这种对解耦模型的简化。生成数值模拟，其使用全双域模型、隔离双域模型和解耦模型来比较在心脏组织的片H中的传播。初步结果表明，解耦模型可能是足够的研究在孤立的整个心脏模型的心脏动力学的一般性质。
Bidomain theory for cardiac tissue assumes two interpenetrating anisotropic media-intracellular (i) and extracellular (e)-connected everywhere via a cell membrane; four local parameters sigma(l,t)(i,e) specify conductivities in the longitudinal (l) and transverse (t) directions with respect to cardiac muscle fibers. The full bidomain model for the propagation of electrical activation consists of coupled elliptic-parabolic partial differential equations for the transmembrane potential v(m) and extracellular potential phi(e), together with quasistatic equations for the flow of current in the extracardiac regions. In this work we develop a preliminary assessment of the consequences of neglecting the effect of the passive extracardiac tissue and intracardiac blood masses on wave propagation in isolated whole heart models and describe a decoupling procedure, which requires no assumptions on the anisotropic conductivities and which yields a single reaction-diffusion equation for simulating the propagation of activation. This reduction to a decoupled model is justified in terms of the dimensionless parameter epsilon = (sigma(l)(i)sigma(t)(e) - sigma(t)(i)sigma(l)(e))/(sigma(l)(i) + sigma(l)(e))(sigma(t)(i) + sigma(t)(e)). Numerical simulations are generated which compare propagation in a sheet H of cardiac tissue using the full bidomain model, an isolated bidomain model, and the decoupled model. Preliminary results suggest that the decoupled model may be adequate for studying general properties of cardiac dynamics in isolated whole heart models.