Advertisement

Extracellular (volume conductor) effect on adjoining cardiac muscle electrophysiology

  • R. Plonsey
  • C. Henriquez
  • N. Trayanova
Physiological Measurement

Abstract

The paper describes the effect of the extracellular volume conductor on the electrophysiological behaviour of an adjoining multifibred cardiac muscle preparation, where the fibres are parallel to the interface and to each other. It is shown how, at any given depth from the interface, an approximating linear-core conductor model can be formulated, where the interstitial resistance per unit length depends on the depth. At the surface the interstitial resistance is zero whereas at the greatest depth it approaches the value that results when the preparation is in oil. Because of this varying total axial resistance with depth, and because of the effect of the total axial resistance on velocity, action potential foot, and maximum rising-phase slope, the wavefront and waveform will also vary with depth. Furthermore these qualities will be anisotropic, since the tissue conductivities are anisotropic. Numerical examples are presented to show that the hypotheses are consistent with experimental results.

Keywords

Cardiac electrophysiology Cardiac muscle Electrocardiography Interstitial resistance Linear core-conductor model Safety factor Time constant of foot Volume conductor 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Clerc, L. (1975) Directional differences of impulse spread in trabecular muscle from mammalian heart.J. Physiol.,255, 335–346.Google Scholar
  2. Hodgkin, A. L. andHuxley, A. F. (1952) A quantitative description of membrane current and its application to conductance and excitation in nerve.,117, 500–544.Google Scholar
  3. Hodgkin, A. L. (1954) A note on conduction velocity.,125, 221–224.Google Scholar
  4. Hunter, P. J., McNaughton, P. A. andNoble, D. (1975) Analytical models of propagation in excitable cells.Progr. Biophys. Molec. Biol.,30, 99–144.CrossRefGoogle Scholar
  5. Kléber, A. G. andRiegger, C. B. (1987) Electrical constants of arterially perfused rabbit papillary muscle.J. Physiol.,385, 307–324.Google Scholar
  6. Plonsey, R. (1969)Bioelectric phenomena. McGraw-Hill, New York.Google Scholar
  7. Plonsey, R. andBarr, R. C. (1984) Current flow patterns in two dimensional anisotropic bisyncytia with normal and extreme conductivities.Biophys. J.,45, 557–571.Google Scholar
  8. Plonsey, R. andBarr, R. C. (1987) Interstitial potentials and their change with depth into cardiac tissue.Biophys. J.,51, 547–555.CrossRefGoogle Scholar
  9. Sommer, J. R. andJohnson, E. A. (1979). Ultrastructure of cardiac muscle. InHandbook of physiology. Section 2. The cardiovascular system. Volume 1. The heart. American Physiological Society, Bethesda, Maryland, 113–186.Google Scholar
  10. Spach, M. S. (1983) The discontinuous nature of electrical propagation in cardiac muscle.Ann. Biomed. Eng.,11, 209–261.CrossRefGoogle Scholar
  11. Spach, M. S., Barr, R. C., Johnson, E. A. andKootsey, J. M. (1973) Cardiac extracellular potentials.Circ. Res.,33, 465–473.Google Scholar
  12. Spach, M. S. andDolber, P. C. (1986) Relating extracellular potentials and their derivatives to anisotropic propagation at a microscopic level in human cardiac muscle.,58, 356–371.Google Scholar
  13. Sperelakis, N. andPicone, J. (1986) Cable analysis in cardiac and smooth muscle bundles.Innov. Tech. Biol. Med.,7, 433–454.Google Scholar
  14. Suenson, M. (1985) Interaction between ventricular cells during the early part of excitation in the ferret heart.Acta. Physiol. Scand.,125, 81–90.Google Scholar
  15. Tasaki, I. andHagiwara, S. (1957) Capacity of muscle fiber membrane.Am. J. Physiol.,188, 423–429.Google Scholar
  16. Tsuboi, N., Kodama, I., Toyama, J. andYamada, K. (1985) Anisotropic conduction properties of canine ventricular muscles.Japan. Circ. J.,49, 487–498.Google Scholar

Copyright information

© IFMBE 1988

Authors and Affiliations

  • R. Plonsey
    • 1
  • C. Henriquez
    • 1
  • N. Trayanova
    • 1
  1. 1.Department of Biomedical EngineeringDuke UniversityDurhamUSA

Personalised recommendations