Period-doubling instability and memory in cardiac tissue.
Theoretical studies have indicated that alternans (period-doubling instability) of action potential duration is associated with a restitution relation with a slope >or=1. However, recent experimental findings suggest that the slope of the restitution relation is not necessarily predictive of alternans. Here, we compared a return map memory model to action potential data from an ionic model and found that the memory model reproduced dynamics that could not be explained by a unidimensional restitution relation. Using linear stability analysis, we determined the onset of the alternans in the memory model and confirmed that the slope of the restitution curve was not predictive.
Fox
Jeffrey J
JJ
Department of Biomedical Sciences and Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.
Bodenschatz
Eberhard
E
Gilmour
Robert F
RF
D000200:Action Potentials / Q000502:physiology; D006321:Heart / Q000502:physiology*; D008955:Models, Cardiovascular