title: Bipolar stimulation of cardiac tissue using an anisotropic bidomain model.
abstract: BACKGROUND
  One of the fundamental electrophysiologic problems that has not yet been completely elucidated is the response of cardiac tissue to externally applied electric currents. A limited number of theoretical and experimental techniques has been used to study the electric behavior of cardiac tissue in the presence of stimulating currents, and to demonstrate that the anisotropy in the passive electrical properties of the tissue plays an important role in the genesis and propagation of the activation wavefront and the resulting potential distributions.
  
  
  RESULTS
  In this work we have applied the finite element method to study the electric and magnetic fields produced by cardiac tissue in response to bipolar current injection, using a linear bidomain model to represent the tissue. We found that the transmembrane potential distribution close to the stimulus electrode has a rather complex geometrical pattern, with adjacent hyperpolarized and depolarized regions.
  
  
  CONCLUSIONS
  This behavior is consistent with previous theoretical and experimental results and may have implications in the study of electrical stimulation of cardiac tissue that are not apparent using other models.
authors.affiliation: Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235.
authors.forename: N G
authors.initials: NG
authors.lastname: Sepulveda
authors.forename: J P
authors.initials: JP
authors.lastname: Wikswo
mesh_terms: D016880:Anisotropy; D003198:Computer Simulation; D004558:Electric Stimulation; D004574:Electromagnetic Fields; D006321:Heart / Q000033:anatomy & histology / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology; D008954:Models, Biological; D009206:Myocardium / Q000166:cytology