Marcotte Christopher D, Grigoriev Roman O
EPSRC Centre for Predictive Modelling in Healthcare, University of Exeter, Devon, EX44QJ, United Kingdom.
School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA.
Chaos. 2017 Sep;27(9):093936. doi: 10.1063/1.5003259.
While spiral wave breakup has been implicated in the emergence of atrial fibrillation, its role in maintaining this complex type of cardiac arrhythmia is less clear. We used the Karma model of cardiac excitation to investigate the dynamical mechanisms that sustain atrial fibrillation once it has been established. The results of our numerical study show that spatiotemporally chaotic dynamics in this regime can be described as a dynamical equilibrium between topologically distinct types of transitions that increase or decrease the number of wavelets, in general agreement with the multiple wavelets' hypothesis. Surprisingly, we found that the process of continuous excitation waves breaking up into discontinuous pieces plays no role whatsoever in maintaining spatiotemporal complexity. Instead, this complexity is maintained as a dynamical balance between wave coalescence-a unique, previously unidentified, topological process that increases the number of wavelets-and wave collapse-a different topological process that decreases their number.
虽然螺旋波破裂被认为与房颤的发生有关，但其在维持这种复杂类型心律失常中的作用尚不清楚。我们使用心脏兴奋的卡玛模型来研究房颤一旦形成后维持其持续存在的动力学机制。我们的数值研究结果表明，该状态下的时空混沌动力学可描述为拓扑结构不同的转换类型之间的动态平衡，这些转换会增加或减少小波数量，这与多小波假说基本一致。令人惊讶的是，我们发现连续的兴奋波破碎成不连续片段的过程在维持时空复杂性方面不起任何作用。相反，这种复杂性是通过波合并（一种独特的、以前未被识别的增加小波数量的拓扑过程）和波崩溃（一种减少小波数量的不同拓扑过程）之间的动态平衡来维持的。
