Spach M S, Kootsey J M
Am J Physiol. 1983 Jan;244(1):H3-22. doi: 10.1152/ajpheart.1983.244.1.H3.
It has long been appreciated that cardiac muscle is composed of individual cells connected by low-resistance connections, but most concepts of cardiac impulse conduction have been based on a simplified model of propagation assuming continuously uniform intracellular resistivity in the direction of propagation. In this article we describe the development of the application of the theory of continuous media to propagation in cardiac muscle and review some of the successes achieved with this theory. New evidence is cited that propagation in cardiac muscle often displays a discontinuous nature. We consider the hypothesis that this previously unrecognized aspect of propagation can be explained by discontinuities in axial resistance related to known structural complexities of cardiac muscle. A major implication is that the combination of discontinuities of effective axial resistivity at several size levels can produce a wide variety of complex abnormalities of propagation, including most currently known cardiac conduction disturbances that have been considered to require spatial nonuniformity of membrane properties.
长期以来，人们一直认识到心肌是由通过低电阻连接相连的单个细胞组成的，但大多数心脏冲动传导的概念都是基于一个简化的传播模型，该模型假设在传播方向上细胞内电阻率连续均匀。在本文中，我们描述了连续介质理论在心肌传播中的应用发展，并回顾了该理论取得的一些成功。引用了新的证据表明心肌中的传播通常表现出不连续的性质。我们考虑这样一个假设，即这种以前未被认识到的传播方面可以通过与心肌已知结构复杂性相关的轴向电阻不连续性来解释。一个主要的含义是，在几个大小水平上有效轴向电阻率的不连续性组合可以产生各种各样复杂的传播异常，包括目前已知的大多数被认为需要膜特性空间不均匀性的心脏传导障碍。
