Biomedical Engineering Reference
In-Depth Information
Fig. 4.
Simulated results for two electrically coupled membrane regions (as in Fig. 1) for which
the SA area is represented by the Irisawa-Noma [10] model and the atrial area is represented by
a modified Beeler-Reuter [2] model with shortened action potential duration. Each symbol
plotted represents a simulation of 2 s, with the simulation results being either (1) failure of the
SA region to pace (NOT PACE,
solid circle
), (2) pacing of the SA region without activation of
the atrial region (PACE BUT NOT DRIVE,
open circle
), or (3) pacing of the SA region with
subsequent activation of the atrial region (PACE AND DRIVE,
open triangle
). In part
a
, the
membrane area of the atrial region. is fixed at 1.0 mm
2
while the membrane area of the SA
region and the coupling resistance are varied. In
b
, the membrane area of the SA region is fixed
at 1.0 mm
2
while the membrane area of the atrial region and the coupling resistance are varied.
The
solid line
separates the graph space into regions of pacing and not pacing. The
dashed line
separates the graph space into regions of successful or unsuccessful driving of the atrial region.
c
and
d
Correspond to
a
and
b
, respectively, except that the magnitude of the slow inward
current is doubled for the SA region in c and d. From Joyner et al. [14].
