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SUMMARY:A novel approach to multidomain modeling of electrical conduction 
 in cardiac tissue - Sachse\, F (Utah)
DTSTART:20090720T151500Z
DTEND:20090720T153000Z
UID:TALK19138@talks.cam.ac.uk
CONTACT:Mustapha Amrani
DESCRIPTION:Various types of models have been developed in the past to stu
 dy electrical conduction in cardiac tissue. Model types include macroscopi
 c approaches e.g. cellular automata and reaction-diffusion systems. In gen
 eral\, macroscopic approaches are based on the assumption that myocytes ar
 e the exclusive cell type in cardiac muscle. However\, cardiac tissue is k
 nown to be a composite material composed of various cell types including -
  in addition to myocytes - fibroblasts\, myofibroblasts\, endothelial\, va
 scular smooth muscle\, and neuronal cells. We hypothesize that heterogenei
 ty of cell type affects electrical conduction. We tested this hypothesis b
 y developing a novel approach for macroscopic multidomain modeling\, apply
 ing the model in computational simulations\, and analyzing the simulation 
 results. \n\nOur multidomain model represents cardiac tissue as a mixture 
 of various cell types. The model is an extension of established cardiac bi
 domain models\, which include a description of intra-myocyte and extracell
 ular conductivities\, currents and potentials in addition to transmembrane
  voltages of myocytes. Our extension added spatial and physical domains as
 sociated with other cell types. Cells in these domains can be electrically
  coupled with each other and with cells from other domains. We implemented
  the model equations based on finite differences and finite element method
 s applying the PETSc toolkit for scientific computation. We applied the mo
 del in exemplary computational simulations of electrical conduction in car
 diac tissue composed of myocytes and fibroblasts. In these simulations\, v
 olume ratios of cells and their inter- and intracellular electrical coupli
 ng were varied. \n\nIn support of our hypothesis\, the simulations showed 
 that cellular heterogeneity\, electrical coupling between myocytes and fib
 roblasts\, and inter-fibroblast coupling have distinct effects on tissue c
 onduction. For example\, myocyte-fibroblast coupling reduced anisotropy of
  conduction velocity only for significant inter-fibroblast coupling. We su
 ggest that these effects can be tested in experimental studies with engine
 ered tissue. Furthermore\, we believe that the presented modeling approach
  provides novel means to understand mechanisms of conduction in diseased a
 nd engineered cardiac tissue.
LOCATION:Seminar Room 1\, Newton Institute
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