Mechanisms of transmurally varying myocyte electromechanics in an integrated computational model.
The mechanical properties of myocardium vary across the transmural aspect of the left ventricular wall. Some of these functional heterogeneities may be related to differences in excitation-contraction coupling characteristics that have been observed in cells isolated from the epicardial, mid-myocardial and endocardial regions of the left ventricle of many species, including canine. Integrative models of coupled myocyte electromechanics are reviewed and used here to investigate sources of heterogeneous electromechanical behaviour in these cells. The simulations (i) illustrate a previously unrecognized role of the transient outward potassium current in mechanical function and (ii) suggest that there may also exist additional heterogeneities affecting crossbridge cycling rates in cells from different transmural regions.
Campbell
Stuart G
SG
Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA.
Flaim
Sarah N
SN
Leem
Chae H
CH
McCulloch
Andrew D
AD
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001696:Biomechanical Phenomena / Q000379:methods; D003198:Computer Simulation; D004594:Electrophysiology / Q000379:methods; D006329:Heart Conduction System / Q000502:physiology*; D006801:Humans; D008955:Models, Cardiovascular; D009200:Myocardial Contraction / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000502:physiology*; D018511:Systems Integration