Death, dynamics
and disorder: Terminating
reentry in
excitable media by dynamically-induced
inhomogeneities
JOHANNES
BREUER1,2 and SITABHRA SINHA1
1The Institute of Mathematical Sciences,
CIT Campus, Taramani, Chennai 600 113, India
2Institute of Theoretical Physics, Technical
University-Berlin, D-10623 Berlin, Germany
E-mail:
sitabhra@imsc.res.in
Abstract. Formation of feedback loops of excitation
waves (reentrant
circuit)
around non-conducting ventricular scar tissue is a
common cause
of cardiac arrhythmias, such as ventricular
tachycardia,
often leading to death. This is typically
treated by
rapid stimulation from an implantable device
(ICD).
However, the mechanisms of reentry termination
success and,
more importantly, failure, are poorly
understood. To study such mechanisms, we simulated
pacing
termination
of reentry in a model of cardiac tissue having
significant
restitution and dispersion properties. Our
results show
that rapid pacing dynamically generates
conduction
inhomogeneities in the reentrant circuit,
leading to
successful pacing termination of tachycardia.
The study
suggests that more effective pacing algorithms
can be
designed by taking into account the role of such
dynamical
inhomogeneities.
Keywords. Reentry; tachycardia; pacing; disorder.
PACS Nos 87.19.Hh;
05.45.Gg; 05.45.-a; 87.10.+e