Analysis of electrically-induced reentrant circuits using nonlinear dynamics tools

Understanding the complex spatio-temporal dynamics of action potential propagation in the heart during arrhythmia is exceedingly difficult. This study applies nonlinear dynamics tools to simplify this task. Using the results of a simulation of an electrical induction of reentry in a sheet of myocardium represented as a bidomain, transmembrane voltages are converted to phase angle and phase "Scatter Plots" (SP), while the evolution of the reentrant wavefronts is examined through the motion of the corresponding phase singularities (PS). As a result, we are able to explore the nature of shock-induced phase resetting in the tissue and the origination of shock-induced reentry in our computational model. Construction of SP\´s as well as calculation of PS\´s allows us to identify the "seeds" of reentry before the wavefront has completed its first cycle. This nontraditional approach to the analysis of electrophysiological phenomena greatly enhances our ability to visualize and conceptualize the dynamics of arrhythmias.