Modulated wave formation in myocardial cells under electromagnetic radiation

Abstract

We exclusively analyze the onset and condition of formation of modulated waves in a diffusive FitzHugh–Nagumo model for myocardial cell excitations. The cells are connected through gap junction coupling. An additive magnetic flux variable is used to describe the effect of electromagnetic induction, while electromagnetic radiation is imposed on the magnetic flux variable as a periodic forcing. We used the discrete multiple scale expansion and obtained, from the model equations, a single differential-difference amplitude nonlinear equation. We performed the linear stability analysis of this equation and found that instability features are importantly influenced by the induced electromagnetic gain. We present the unstable and stable regions of modulational instability (MI). The resulting analytic predictions are confirmed by numerical experiments of the generic equations. The results reveal that due to MI, an initial steady state that consisted of a plane wave with low amplitude evolves into a modulated localized wave patterns, soliton-like in shape, with features of synchronization. Furthermore, the formation of periodic pulse train with breathing motion presents a disappearing pattern in the presence of electromagnetic radiation. This could provide guidance and better understanding of sudden heart failure exposed to heavily electromagnetic radiation.

Effect of temperature fluctuation on the localized pattern of action potential in cardiac tissue

“…without losing their vital characteristics features. It has recently being widely extended to many other physical and biological media 4,31,32 . Through the multiple scale analysis expansions, the first particle of chain network (n = 0) , is set into oscillations when subjected to an external forcing with the natural frequency .…”

“…This expansion enables the deduction of a more manipulable equation from the model without losing their vital characteristics features. It has recently being widely extended to many other physical and biological media 4 , 31 , 32 .…”

“…This result partly confirms the investigations of Lu et al 41 and Zhao et al 42 , obtained in the case of neuronal electrical activity. As perspective, a more realistic model can be envisaged to include the physical law of electromagnetic induction and radiation 4,31,43 , time delay 44,45 , noise 46 , autapses 47 and the action of chemical synapses 48 . Researchers may further build neural circuits coupled with thermistors, whose conductance is temperature dependent in other to investigate cooperative behaviors such synchronization consensus due to heat capture 49 .…”

“…Aliev et al modified the FHN model so that it describes adequately the dynamics of pulse propagation in the canine myocardium 20 . Indeed, the revised version of the FHN are often used to describe cardiac tissue electrical activities 4 , 21 , 25 . The evolution of the network dynamics under temperature fluctuation and nonlinear coupling 26 in cardiac tissue is described by: where and N represents the position of excitable node in the network.…”

“…Understanding mode transition in electrical activity in cardiac tissue from a normal rhythm to various pathological states has aroused the interest of several researchers 1 – 4 . The electrical activity in cardiac tissue and excitable network have been shown to be affected by a number of factors.…”