Theory of action potential wave block at-a-distance in the heart
Theory of action potential wave block at-a-distance in the heart
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DOI：
10.1103/physreve.75.021910
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发表时间：
2007-02-01
影响因子：
2.4
通讯作者：
Otani, Niels F.
中科院分区：
文献类型：
--
作者：
Otani, Niels F.
动作电位波在离其源有限距离处的传播失败（所谓的II型阻滞）可能导致心脏中的螺旋波形成或波分裂，这些现象被认为是致命性和非致命性心律失常的基础。在这项研究中，我们开发了一个充分条件，这种类型的块在一个均匀的，空间一维系统。使用拓扑参数，我们发现，II型块的波将总是发生时，在有限的时间范围内发射，如果在刺激部位测量的前一波的后缘的速度，是小于发射的波的速度与最小舒张间期（DI）的传播是可能的。这种“阻塞条件”是鲁棒的，即使在包括记忆和波回电紧张效应时仍然有效。该条件表明，当波以不规则的时间间隔启动时，II型阻滞会大大促进，使得（1）连续波的速度尽可能不同，（2）每个波之前的DI尽可能经常落在动作电位时程恢复曲线的陡峭倾斜部分。预测的阻塞条件产生块的刺激之间的时间间隔的设置被认为是与这些准则相一致，也同意与耦合映射的计算机仿真模型，由四个快速和不规则定时的刺激波发射的情况下。
Propagation failure of an action potential wave at a finite distance from its source (so-called type-II block) may cause spiral wave formation or wave breakup in the heart, phenomena that are believed to underlie lethal and nonlethal heart rhythm disorders. In this study, we develop a sufficient condition for this type of block in a homogeneous, spatially one-dimensional system. Using a topological argument, we find that type-II block of a wave will always occur when launched within a finite range of times if the velocity of the trailing edge of the preceding wave, as measured at the stimulus site, is smaller than the velocity of a wave launched with the minimum diastolic interval (DI) for which propagation is possible. This "blocking condition" is robust, remaining valid even when memory and waveback electrotonic effects are included. The condition suggests that type-II block is greatly facilitated when waves are initiated at irregular intervals in time such that (1) the velocities of consecutive waves are as different as possible and (2) the DIs preceding each wave fall on the steeply sloped portion of the action potential duration restitution curve as often as possible. The set of timing intervals between stimuli that are predicted by the blocking condition to produce block are found to be consistent with these guidelines, and also to agree well with a coupled-maps computer simulation model, for the case of waves launched by four rapidly and irregularly timed stimuli.