title: Phase-resolved analysis of the susceptibility of pinned spiral waves to far-field pacing in a two-dimensional model of excitable media.
abstract: Life-threatening cardiac arrhythmias are associated with the existence of stable and unstable spiral waves. Termination of such complex spatio-temporal patterns by local control is substantially limited by anchoring of spiral waves at natural heterogeneities. Far-field pacing (FFP) is a new local control strategy that has been shown to be capable of unpinning waves from obstacles. In this article, we investigate in detail the FFP unpinning mechanism for a single rotating wave pinned to a heterogeneity. We identify qualitatively different phase regimes of the rotating wave showing that the concept of vulnerability is important but not sufficient to explain the failure of unpinning in all cases. Specifically, we find that a reduced excitation threshold can lead to the failure of unpinning, even inside the vulnerable window. The critical value of the excitation threshold (below which no unpinning is possible) decreases for higher electric field strengths and larger obstacles. In contrast, for a high excitation threshold, the success of unpinning is determined solely by vulnerability, allowing for a convenient estimation of the unpinning success rate. In some cases, we also observe phase resetting in discontinuous phase intervals of the spiral wave. This effect is important for the application of multiple stimuli in experiments.
authors.affiliation: Drittes Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany. philip.bittihn@ds.mpg.de
authors.forename: Philip
authors.initials: P
authors.lastname: Bittihn
authors.forename: Amgad
authors.initials: A
authors.lastname: Squires
authors.forename: Gisa
authors.initials: G
authors.lastname: Luther
authors.forename: Eberhard
authors.initials: E
authors.lastname: Bodenschatz
authors.forename: Valentin
authors.initials: V
authors.lastname: Krinsky
authors.forename: Ulrich
authors.initials: U
authors.lastname: Parlitz
authors.forename: Stefan
authors.initials: S
authors.lastname: Luther
mesh_terms: D001145:Arrhythmias, Cardiac / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D004558:Electric Stimulation; D008954:Models, Biological