A Model Study of the Effect of the Intercalated Discs on Discontinuous Propagation in Cardiac Muscle

  • Pedro J. Diaz
  • Yoram Rudy
  • Robert Plonsey
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 161)


There is considerable evidence (1,13,14,22,23) to support the existence of low resistance end-to-end junctions (gap junctions or connexons (10,12,17) which lie in the intercalated discs that make up the associated end-to-end plasma membranes of cardiac muscle cells. Even though these gap junctions are low resistance, they represent a significant discontinuity in the conductive medium. Indeed, while these low resistance contacts are low in the sense of permitting an adequate current to flow and excite the postjunctional cell, an often quoted value for the intercalated disc resistance, 1 ohm-cm2, would be an impediment to axial current flow comparable to the entire myoplasm of the cell. In order to study the effects of these discontinuities due to the intercalated discs on propagation in cardiac muscle a “microscopic” discontinuous cable model which includes the intercalated discs was developed.


Cardiac Muscle Conduction Velocity Sharp Discontinuity Cable Model Discontinuous Model 
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  1. 1.
    Barr, L., M.M. Dewey and W. Berger. Propagation of action potentials and the structure of the nexus in cardiac muscle. J. Gen. Physiol. 48:797–823, 1965.PubMedCrossRefGoogle Scholar
  2. 2.
    Beeler, G.W. and H. Reuter. Reconstruction of the action potential of ventricular myocardial fibres. J. Physiol. London 286:177–210, 1977.Google Scholar
  3. 3.
    Chapman, R.A. and C.H. Fry. An analysis of the cable properties of frog ventricular myocardium. J. Physiol. London 283:263–281, 1978.PubMedGoogle Scholar
  4. 4.
    Clerc, L. Directional differences of impulse spread in trabecular muscle from mammalian heart. J. Physiol. London 255:335–346, 1976.PubMedGoogle Scholar
  5. 5.
    Crank, J. and P. Nicolson. A practical method for numerical evaluation of solutions of partial differential equations of the heat conduction type. Proc. Cambridge Phil. Soc. 43:50–77, 1947.CrossRefGoogle Scholar
  6. 6.
    Heppner, D.B. and R. Plonsey. Simulation of electrical interaction of cardiac cells. Biophys J. 10:1057–1075, 1970.PubMedCrossRefGoogle Scholar
  7. 7.
    Hodgkin, A.L. and Huxley, A.F. A quantitative description of membrane current and its application to conduction and excitation in nerve. J. Physiol. London 117:500–544, 1952.PubMedGoogle Scholar
  8. 8.
    Lowenstein, W.R. Junctional intercellular communication: The cell-to-cell membrane channel. Physiol. Rev. 61:829–913, 1981.Google Scholar
  9. 9.
    McAllister, R.E., D. Noble and R.W. Tsien. Reconstruction of the electrical activity of cardiac Purkinje fibers. J. Physiol. London 251:1–59, 1975.PubMedGoogle Scholar
  10. 10.
    McNutt, N.S. and R.S. Weinstein. Membrane ultrastructure at mammalian intercellular junctions. Prog. Biophys. Mol. Biol. 26:45–101, 1973.PubMedCrossRefGoogle Scholar
  11. 11.
    Miller, W.T. III and D.B. Geselowitz. Simulation studies of the electrocardiogram: I.The normal heart. Circ. Res. 43:301–323, 1978.PubMedGoogle Scholar
  12. 12.
    Page, E. and L.P. McAllister. Studies on the intercalated discs of rat ventricular myocardial cells. J. Ultrastruct. Res. 43:388–411, 1973.PubMedCrossRefGoogle Scholar
  13. 13.
    Page, E. and Y. Shibata. Permeable junctions between cardiac cells. Ann. Rev. Physiol. 43:431–442, 1981.CrossRefGoogle Scholar
  14. 14.
    Pollack, G.H. Intercellular coupling in the atrioventricular node and other tissues of the rabbit heart. J. Physiol. London 255: 275–298, 1976.PubMedGoogle Scholar
  15. 15.
    Plonsey, R. Action potential sources and their volume conductor fields. Proc. IEEE 65:601–611, 1976.CrossRefGoogle Scholar
  16. 16.
    Plonsey, R. and Y. Rudy. Electrocardiogram sources in a two dimensional anisotropic activation model. Med. Biol. Engr. Comput. 18:87–95, 1980.CrossRefGoogle Scholar
  17. 17.
    Revel, J.P. and M.J. Karnovsky. Hexagonal arrays of subunits in intercellular junctions of the mouse heart and liver. J. Cell Biol. 12:571–588, 1962.PubMedCrossRefGoogle Scholar
  18. 18.
    Rush, S. and H. Larsen . A practical algorithm for solving dynamic membrane equations. IEEE BME 25:389–392, 1978.CrossRefGoogle Scholar
  19. 19.
    Sharp, G. and Joyner, R.W. Simulated propagation of cardiac action potentials. Biophysical J. 31:403–424, 1980.CrossRefGoogle Scholar
  20. 20.
    Spach, M.S., W.T. Miller III, D.B. Geselowitz, R.C. Barr, J.M. Kootsey and E.A. Johnson. The discontinuous nature of propagation in normal cardiac muscle: Evidence for recurrent discontinuities of intra-cellular resistance that affect the membrane currents. Circulation Res. 48:39–56, 1981.PubMedGoogle Scholar
  21. 21.
    Spira, A.W. The nexus in the intercalated disc of the canine heart: Quantitative data for the estimation of its resistance. J. Ultrastruct. Res. 34:409–425, 1971.PubMedCrossRefGoogle Scholar
  22. 22.
    Weidmann, S. The diffusion of radiopotassium across intercalated disks of mammalian cardiac muscle. J. Physiol. London 187:323–342, 1966.PubMedGoogle Scholar
  23. 23.
    Woodbury, J.W. and W.E. Crill. On the problem of impulse conduction in the atrium. In: Nervous Inhibition ,edited by L. Florey. New York: Plenum, 1961, pp. 24–35.Google Scholar

Copyright information

© Plenum Press, New York 1983

Authors and Affiliations

  • Pedro J. Diaz
    • 1
  • Yoram Rudy
    • 1
  • Robert Plonsey
    • 1
  1. 1.Department of Biomedical EngineeringCase Western Reserve UniversityClevelandUSA

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