Period-doubling bifurcation to alternans in paced cardiac tissue: crossover from smooth to border-collision characteristics.
We investigate, both experimentally and theoretically, the period-doubling bifurcation to alternans in heart tissue. Previously, this phenomenon has been modeled with either smooth or border-collision dynamics. Using a modification of existing experimental techniques, we find a hybrid behavior: Very close to the bifurcation point, the dynamics is smooth, whereas further away it is border-collision-like. The essence of this behavior is captured by a model that exhibits what we call an unfolded border-collision bifurcation. This new model elucidates that, in an experiment, where only a limited number of data points can be measured, the smooth behavior of the bifurcation can easily be missed.
Berger
Carolyn M
CM
Department of Physics, Duke University, Durham, North Carolina 27708, USA.
Zhao
Xiaopeng
X
Schaeffer
David G
DG
Dobrovolny
Hana M
HM
Krassowska
Wanda
W
Gauthier
Daniel J
DJ
D000200:Action Potentials; D006321:Heart; D006801:Humans; D008955:Models, Cardiovascular