Scroll-wave dynamics in the presence of ionic and conduction inhomogeneities in an anatomically realistic mathematical model for the pig heart
R. Majumdera, R. Panditb, A. V. Panfilovc
aLaboratory of Experimental Cardiology, Dept. of Cardiololgy, Heart Lung Center, Leiden University Medical center,
2333ZA Leiden, the Netherlands
bCentre for Condensed Matter Theory, Dept. of Physics, Indian Institute of Science, 560012 Bangalore, India;
Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
cDept. of Physics and Astronomy, Gent University, Krijgslaan 281, S9, 9000 Gent, Belgium;
Moscow Institute of Physics and Technology (State University), 141700 Dolgoprudny, Russia
Abstract
Nonlinear waves of the reaction-diffusion (RD) type occur in many biophysical systems, including the
heart, where they initiate cardiac contraction. Such waves can form vortices called scroll waves, which result
in the onset of life-threatening cardiac arrhythmias. The dynamics of scroll waves is affected by the presence
of inhomogeneities, which, in a very general way, can be of ionic type, i.e., they affect the reaction part, or
conduction type, i.e., they affect the diffusion part of an RD-equation. We demostrate, for the first time, by
using a state-of-the-art, anatomically realistic model of the pig heart, how differences in the geometrical and
biophysical nature of such inhomogeneities can influence scroll-wave dynamics in different ways. Our study
reveals that conduction-type inhomogeneities become increasingly important at small length scales, i.e., in the
case of multiple, randomly distributed, obstacles in space at the cellular scale (0.2–0.4mm). Such configurations
can lead to scroll-wave break up. In contrast, ionic inhomogeneities, affect scroll-wave dynamics significantly
at large length scales, when these inhomogeneities are localized in space at the tissue level (5–10mm). In such
configurations, these inhomogeneities can attract scroll waves, by pinning them to the heterogeneity, or lead
to scroll-wave breakup.