Title
Modelling the effect of gap junctions on tissue-level cardiac electrophysiology.
Abstract
When modelling tissue-level cardiac electrophysiology, a continuum approximation to the discrete cell-level equations, known as the bidomain equations, is often used to maintain computational tractability. Analysing the derivation of the bidomain equations allows us to investigate how microstructure, in particular gap junctions that electrically connect cells, affect tissue-level conductivity properties. Using a one-dimensional cable model, we derive a modified form of the bidomain equations that take gap junctions into account, and compare results of simulations using both the discrete and continuum models, finding that the underlying conduction velocity of the action potential ceases to match up between models when gap junctions are introduced at physiologically realistic coupling levels. We show that this effect is magnified by: (i) modelling gap junctions with reduced conductivity; (ii) increasing the conductance of the fast sodium channel; and (iii) an increase in myocyte length. From this, we conclude that the conduction velocity arising from the bidomain equations may not be an accurate representation of the underlying discrete system. In particular, the bidomain equations are less likely to be valid when modelling certain diseased states whose symptoms include a reduction in gap junction coupling or an increase in myocyte length.
Year
DOI
Venue
2012
10.1007/s11538-013-9927-1
HSB
Keywords
Field
DocType
Cardiac electrophysiology, Bidomain, Gap junctions, Homogenisation
Mathematical optimization,Gap junction,Homogenization (chemistry),Simulation,Cardiac electrophysiology,Continuum (design consultancy),Classical mechanics,Discrete system,Mathematics
Journal
Volume
Issue
ISSN
76
2
1522-9602
Citations 
PageRank 
References 
0
0.34
1
Authors
3
Name
Order
Citations
PageRank
Doug Bruce100.34
Pras Pathmanathan211111.77
Jonathan Whiteley311913.02