ELECTROMECHANICAL COUPLING IN CARDIAC DYNAMICS: THE ACTIVE STRAIN APPROACH
ELECTROMECHANICAL COUPLING IN CARDIAC DYNAMICS: THE ACTIVE STRAIN APPROACH
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DOI：
10.1137/100788379
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发表时间：
2011-01-01
影响因子：
1.9
通讯作者：
Quarteroni, A.
中科院分区：
文献类型：
--
作者：
Ambrosi, D.;Arioli, G.;Quarteroni, A.
心脏力学和电信号之间的耦合是在一个非标准的框架中解决的，在这个框架中，电位决定了肌肉的主动应变（而不是应力）。导致我们做出这种选择的生理和数学动机已被阐明。假设电信号的传播由FitzHugh-Nagumo方程控制，该方程在具有变形基底的材料坐标中重写；并与刚性情况进行了比较，讨论了脉冲速度和宽度的差异。指出了粘弹性的作用。我们证明了坐标的拉伸不足以产生机电反馈；然而，它可以使扰动的能量增加到足以产生行进脉冲：报告了能量估计和数值证据。为了支持这些结论，二维数值模拟显示了电传播和机械应变之间的相互作用。
The coupling between cardiac mechanics and electric signaling is addressed in a nonstandard framework in which the electrical potential dictates the active strain (not stress) of the muscle. The physiological and mathematical motivations leading us to this choice are illustrated. The propagation of the electric signal is assumed to be governed by the FitzHugh-Nagumo equations, rewritten in material coordinates with a deforming substrate; the solution is compared with the rigid case, and differences in celerity and width of a pulse are discussed. The role of viscoelasticity is pointed out. We show that the stretching of coordinates is insufficient to originate electromechanical feedback; nevertheless, it can increase the energy of a perturbation enough to produce a traveling pulse: an energy estimate and numerical evidence are reported. To support these conclusions, numerical simulations in two dimensions show the interplay between electric propagation and mechanical strain.