International Institute of Information Technology (IIIT-Bhubaneswar), Gothapatna, Po: Malipada, Bhubaneswar 751003, India.
Department of Physics and Astronomy, Gent University, Krijgslaan 281, S9, 9000 Gent, Belgium.
Phys Rev E. 2017 Feb;95(2-1):022405. doi: 10.1103/PhysRevE.95.022405. Epub 2017 Feb 13.
We present systematic numerical studies of the possible effects of the coupling of human endocardial and Purkinje cells at cellular and two-dimensional tissue levels. We find that the autorhythmic-activity frequency of the Purkinje cell in a composite decreases with an increase in the coupling strength; this can even eliminate the autorhythmicity. We observe a delay between the beginning of the action potentials of endocardial and Purkinje cells in a composite; such a delay increases as we decrease the diffusive coupling, and eventually a failure of transmission occurs. An increase in the diffusive coupling decreases the slope of the action-potential-duration-restitution curve of an endocardial cell in a composite. By using a minimal model for the Purkinje network, in which we have a two-dimensional, bilayer tissue, with a layer of Purkinje cells on top of a layer of endocardial cells, we can stabilize spiral-wave turbulence; however, for a sparse distribution of Purkinje-ventricular junctions, at which these two layers are coupled, we can also obtain additional focal activity and many complex transient regimes. We also present additional effects resulting from the coupling of Purkinje and endocardial layers and discuss the relation of our results to the studies performed in anatomically accurate models of the Purkinje network.
我们呈现了在细胞和二维组织水平上，人类心内膜和浦肯野细胞耦合可能产生的影响的系统数值研究。我们发现，复合体内浦肯野细胞的自律活动频率随耦合强度的增加而降低；这甚至可以消除自律性。我们观察到复合体内心内膜和浦肯野细胞的动作电位起始之间存在延迟；随着扩散耦合的减少，这种延迟会增加，最终会发生传输失败。扩散耦合的增加会降低复合体内心内膜细胞动作电位时程补偿曲线的斜率。通过使用浦肯野网络的最小模型，其中我们有一个二维双层组织，一层是浦肯野细胞，一层是心内膜细胞，我们可以稳定螺旋波湍流；然而，对于浦肯野-心室连接稀疏分布的情况，这两层是耦合的，我们也可以获得额外的局灶性活动和许多复杂的瞬态状态。我们还介绍了浦肯野和心内膜层耦合产生的其他影响，并讨论了我们的结果与在浦肯野网络的解剖精确模型中进行的研究之间的关系。
