Special Session 40: Applications of dynamical systems in medicine and biology

Cardiomyocyte Dynamics: From Low Dimensional To Realistic Models
Roberto Barrio
University of Zaragoza
Spain
Co-Author(s):    R. Barrio, H. Kitajima, M.A. Martinez, S. Serrano
Abstract:
Early afterdepolarizations (EADs) are abnormal behaviors that can lead to heart failure and even cardiac death. In this presentation, we review recent results and we mathematically investigate the occurrence and development of these phenomena in two realistic ventricular myocyte models: the rabbit model of Sato (2009) and the human model of O'Hara (2011). These models are of high dimension, 27 and 41 respectively, so a mix of techniques must be used in their study. We connect the results with a reduced low-dimensional model, the Luo-Rudy cardiomyocyte model (1991). The combined use of analytical and numerical techniques allows us to propose a global conjecture of a mathematical mechanism of EAD creation in low- and high-dimensional models. By examining the bifurcation structure of the model, we elucidate the dynamical elements associated with these patterns and their transitions. Using a fast-slow analysis, we explore the emergence and evolution of EAD in the low-dimensional model and develop new methodologies for fast-slow decomposition for the realistic high-dimensional O`Hara model. This decomposition has allowed us to propose some new theoretical techniques for the control of prearrhythmia situations.