Steinberg Benjamin E, Glass Leon, Shrier Alvin, Bub Gil
Programme in Cell Biology, Hospital for Sick Children and Institute of Medical Science, University of Toronto, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.
Philos Trans A Math Phys Eng Sci. 2006 May 15;364(1842):1299-311. doi: 10.1098/rsta.2006.1771.
Electrical heterogeneities play a role in the initiation of cardiac arrhythmias. In certain pathological conditions such as ischaemia, current sinks can develop in the diseased cardiac tissue. In this study, we investigate the effects of changing the amount of heterogeneity and intercellular coupling on wavefront stability in a cardiac cell culture system and a mathematical model of excitable media. In both systems, we observe three types of behaviour: plane wave propagation without breakup, plane wave breakup into spiral waves and plane wave block. In the theoretical model, we observe a linear decrease in propagation velocity as the number of heterogeneities is increased, followed by a rapid, nonlinear decrease to zero. The linear decrease results from the heterogeneities acting independently on the wavefront. A general scaling argument that considers the degree of system heterogeneity and the properties of the excitable medium is used to derive a dimensionless parameter that describes the interaction of the wavefront with the heterogeneities.
电不均匀性在心律失常的引发中起作用。在某些病理状况下，如缺血时，患病心肌组织中会形成电流汇集区。在本研究中，我们在心肌细胞培养系统和可兴奋介质数学模型中，研究改变不均匀性数量和细胞间耦合对波前稳定性的影响。在这两个系统中，我们观察到三种类型的行为：无破裂的平面波传播、平面波破裂成螺旋波以及平面波阻滞。在理论模型中，我们观察到随着不均匀性数量增加，传播速度呈线性下降，随后迅速非线性下降至零。线性下降是由于不均匀性独立作用于波前。一个考虑系统不均匀性程度和可兴奋介质特性的通用标度论证被用于推导一个无量纲参数，该参数描述波前与不均匀性的相互作用。
