Wave-train induced unpinning of weakly anchored vortices in excitable media

TL;DR

This paper demonstrates that wave-trains can unpin vortices attached to small obstacles in excitable media, with implications for cardiac tissue, by analyzing the relationship between obstacle size, wave frequency, and unpinning.

Contribution

It reveals that vortices attached to obstacles smaller than their core radius can be unpinned via pacing, expanding understanding of vortex dynamics in excitable media.

Findings

Unpinning is possible for obstacles smaller than the vortex core radius.

Unpinning frequency increases with obstacle size.

Decreased medium excitability facilitates vortex removal.

Abstract

A free vortex in excitable media can be displaced and removed by a wave-train. However, simple physical arguments suggest that vortices anchored to large inexcitable obstacles cannot be removed similarly. We show that unpinning of vortices attached to obstacles smaller than the core radius of the free vortex is possible through pacing. The wave-train frequency necessary for unpinning increases with the obstacle size and we present a geometric explanation of this dependence. Our model-independent results suggest that decreasing excitability of the medium can facilitate pacing-induced removal of vortices in cardiac tissue.