The Dynamics of Sustained Reentry in a Loop Model with Discrete Gap Junction Resistance
Abstract
Dynamics of reentry are studied in a one dimensional loop of model cardiac cells with discrete intercellular gap junction resistance (
R
). Each cell is represented by a continuous cable with ionic current given by a modified Beeler-Reuter formulation. For
R
below a limiting value, propagation is found to change from period-1 to quasi-periodic (
QP
) at a critical loop length (
L
crit
) that decreases with
R
. Quasi-periodic reentry exists from
L
crit
to a minimum length (
L
min
) that is also shortening with
R
. The decrease of
L
crit
(R)
is not a simple scaling, but the bifurcation can still be predicted from the slope of the restitution curve giving the duration of the action potential as a function of the diastolic interval. However, the shape of the restitution curve changes with
R
.