Nicole Cusimano, Luca Gerardo-Giorda, Alessio Gizzi,
"A space-fractional bidomain framework for cardiac electrophysiology: 1D alternans dynamics"
, in Chaos: An Interdisciplinary Journal of Nonlinear Science, Vol. 31, Nummer 7, AIP Publishing LLC, 7-2021, ISSN: 1054-1500
A space-fractional bidomain framework for cardiac electrophysiology: 1D alternans dynamics
Sprache des Titels:
Cardiac electrophysiology modeling deals with a complex network of excitable cells forming an intricate syncytium: the heart. The electrical activity of the heart shows recurrent spatial patterns of activation, known as cardiac alternans, featuring multiscale emerging behavior. On these grounds, we propose a novel mathematical formulation for cardiac electrophysiology modeling and simulation incorporating spatially non-local couplings within a physiological reaction?diffusion scenario. In particular, we formulate, a space-fractional electrophysiological framework, extending and generalizing similar works conducted for the monodomain model. We characterize one-dimensional excitation patterns by performing an extended numerical analysis encompassing a broad spectrum of space-fractional derivative powers and various intra- and extracellular conductivity combinations. Our numerical study demonstrates that (i) symmetric properties occur in the conductivity parameters? space following the proposed theoretical framework, (ii) the degree of non-local coupling affects the onset and evolution of discordant alternans dynamics, and (iii) the theoretical framework fully recovers classical formulations and is amenable for parametric tuning relying on experimental conduction velocity and action potential morphology.
Heart disease affects most of the population worldwide. Irregular electrical patterns represent the primary factor leading to sudden cardiac death irrespective of the enormous scientific and technological effort in understanding their intrinsic mechanisms. Mathematical and computational tools have undoubtedly been key players in this quest and still are. Today?s challenge is how to incorporate highly heterogeneous microscopic features into a reliable numerical tool that can be effectively used at the scale of a whole heart. We explore this aspect by proposing a generalized space-fractional bidomain framework for modeling and simulation of cardiac electrophysiology in extended spatial domains. By enriching our previous efforts on this novel rationale,1 we demonstrate that the onset and evolution of irregular electrical patterns, such as cardiac alternans, are affected by the degree of non-local coupling. Our ultimate objective is to unveil novel critical mechanisms that can induce the onset of cardiac arrhythmias in view of future clinical validation.
Sprache der Kurzfassung:
Chaos: An Interdisciplinary Journal of Nonlinear Science