Role of the dispersion of refractoriness on cardiac reentries.
Math Biosci
; 157(1-2): 253-67, 1999 Mar 15.
Article
in En
| MEDLINE
| ID: mdl-10194932
ABSTRACT
We used computer simulation to study the possible role of the dispersion of cellular coupling, refractoriness or both, in the mechanisms underlying cardiac arrhythmias. Local ischemia was first assumed to induce cell to cell dispersion of the coupling resistance (case 1), refractory period (case 2), or both (case 3). Our numerical experiments based on the van Capelle and Durrer model showed that vortices could not be induced. On the other hand, with cellular properties dispersed in a patchy way within the ischemic zone, a single activation wave could give rise to abnormal activities. This demonstrates the stability of the wave front under small inhomogeneities. Probabilities of reentry, estimated for the three cases cited above showed that a severe alteration of the coupling resistance may be an important factor in the genesis of reentry. Moreover, use of isochronal maps revealed that vortices were both stable and sustained with an alteration of the coupling alone or along with a reduction of the action potential duration. Conversely, simulations with reduction of the refractoriness alone, inducing only transient patterns, could exhibit functionally determined reentries.
Search on Google
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Refractory Period, Electrophysiological
/
Computer Simulation
/
Tachycardia, Atrioventricular Nodal Reentry
/
Models, Cardiovascular
Type of study:
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
Math Biosci
Year:
1999
Document type:
Article
Affiliation country:
France