Study of unipolar electrogram morphology in a computer model of atrial fibrillation. Jacquemet, V., Virag, N., Ihara, Z., Dang, L., Blanc, O., Zozor, S., Vesin, J., Kappenberger, L., & Henriquez, C. j-JCE, 14(10 Suppl):S172–S179, 2003.
bibtex   
@Article{RSM:Jac2003,
  author =       "V. Jacquemet and N. Virag and Z. Ihara and L. Dang and
                 O. Blanc and S. Zozor and J.M. Vesin and L.
                 Kappenberger and C.S. Henriquez",
  title =        "Study of unipolar electrogram morphology in a computer
                 model of atrial fibrillation.",
  journal =      j-JCE,
  year =         "2003",
  volume =       "14",
  number =       "10 Suppl",
  pages =        "S172--S179",
  robnote =      "INTRODUCTION: In this study, data from computer models
                 were studied to relate features of the signals to the
                 underlying dynamics and tissue substrate. METHODS AND
                 RESULTS: A computer model of entire human atria with a
                 gross fiber architecture based on histology and
                 membrane kinetics based on the Courtemanche et al.
                 atrial model was developed to simulate paced activation
                 and simulated AF. Unipolar electrograms were computed
                 using a current source approximation at 256 sites in
                 right atrium, to simulate a mapping array. The results
                 show the following: (1) In a homogeneous and isotropic
                 tissue, the presence of highly asymmetric electrograms
                 is rare (<2\%), although there is a marked variability
                 in amplitude and symmetry. (2) The introduction of
                 anisotropy increases this variability in symmetry and
                 amplitude of the, electrograms especially for
                 propagation across fibers. The percentage of highly
                 asymmetric electrograms increases to 12\% to 15\% for
                 anisotropy ratios greater than 3:1. (3) Multiphasic and
                 fractionated electrograms are rarely seen in the model
                 with uniform properties but are more common (15\%-17\%)
                 in a model including regions with abrupt changes in
                 conductivity. Beat-to-beat variations in the occurrence
                 of multiphasic signals are possible with fixed anatomic
                 heterogeneity, due to beat-to-beat variations in the
                 direction of the wavefront relative to the
                 heterogeneity. CONCLUSION: Analysis of the amplitude
                 and symmetry of unipolar atrial electrograms can
                 provide information about the electrophysiologic
                 substrate maintaining AF.",
  bibdate =      "Mon Nov 20 07:50:07 2006",
}

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