George Washington University Medical Center

In a pursuit of a spiral waves

Kostya Agladze

Abstract: Excitation waves are known to play an important role in the self-organization of a wide variety of nonlinear media, including biological, chemical, and ecological systems. An important prerequisite for these waves is the coupling of local excitable kinetics with diffusion transport. One of the most intriguing examples of dynamic structures in excitable systems is rotating spiral waves. Although spiral waves were discovered in a variety of active media, their study was in major part inspired by the relevance of this topic to the functioning of heart in the normal and pathological conditions. While during last three decades plenty of information about dynamics of rotating waves was accumulated from the experiments on model systems and computer simulations, most of it was not justified for the cardiac tissue for an apparent reason of difficulty of direct observations. Thus, understanding of spiral wave origination and termination, as well as many approaches to control spiral waves (such as pacing, for instance) remain based on theoretical concepts and data obtained from computer simulations. Recent success in development of an experimental model based on the cardiomyocyte layers and in methods of visualization of excitation waves with the aid of potential sensitive and Ca++ sensitive dyes creates an avenue for new studies with the long term goals to develop clinically applicable methods for controlling and terminating rotating waves in cardiac tissue