Advertisement

Annals of Biomedical Engineering

, Volume 17, Issue 4, pp 437–455 | Cite as

Dipole moment ofin vivo and isolated perfused rabbit hearts

  • Clifford V. Nelson
  • Brian C. Hodgkin
Article
  • 36 Downloads

Abstract

We have measured magnitude and location of heart dipole moment during QRS in 46 New Zealand white rabbits. The spatial magnitude curve had one to three peaks. Mean values were M1=80±10 μA-cm (N=5) pointing to right anterior and caudal, M2=260±15 μA-cm (N=42) directed slightly to left of due anterior and caudal, and M3=236±9 μA-cm (N=43) pointing towards left posterior and cephalad. The mean thorax resistivity was 250 ohm-cm. For 23 rabbits, M2/M3>1 and for 16 rabbits, M2/M3<1. Mean times of occurrence of the three peaks were 5.8, 11.2, and 19.6 ms, respectively. Spatial magnitude curves for hearts perfused at the center of a sphere showed usually one major peak at about 19 ms. Locuscardiograms ofin vivo hearts were also measured. By comparing M values forin vivo and isolated hearts, we found that M1 values agreed closely but mean M2 measured from the heartsin vivo was 2.5 times that for the isolated hearts, and M3 forin vivo hearts was about two-thirds that for isolated hearts. We relate these differences to the effects of intracardiac blood and lungs on the measured dipole moment.

Keywords

Rabbit heart Rabbit dipole moment Rabbit vectorcardiogram Thorax inhomogeneity Dipole location 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Agnoli, G.C.; Cotti, E. Senso e velocita di propogazione dell'eccitamento nella parete ventricolare del cuore di coniglio. Boll Soc Ital Biol Sper. 36:742–745; 1960.PubMedGoogle Scholar
  2. 2.
    Agnoli, G.C.; Cotti, E. La propagazione intramurale dell'eccitamento nel ventricolo sinistro del cuore isolato di coniglio. Arch Sci Biol. 44:49–95; 1960.Google Scholar
  3. 3.
    Bayley, R.H.; Berry, P.M. “Body surface” potentials produced by the eccentric dipole in the heart wall of the nonhomogeneous volume conductor. Am Heart J. 65:200–207; 1963.CrossRefPubMedGoogle Scholar
  4. 4.
    Brody, D.A. A theoretical analysis of intracavitary blood mass influence on the heart-lead relationship. Circ Res. 4:731–738; 1956.PubMedGoogle Scholar
  5. 5.
    Brody, D.A.; Cox, J.W., Jr.; Keller, F.W.; Wennemark, J.R. Dipole ranging in isolated rabbit hearts before and after right bundle branch block. Cardiovasc Res. 8:37–45; 1974.PubMedGoogle Scholar
  6. 6.
    DeGuise, J.; Gulrajani, R.M.; Savard, P.; Guardo, R.; Roberge, F.A. Inverse recovery of two moving dipoles from simulated surface potential distributions in a realistic human torso model. IEEE Trans Biomed Eng, BME-32:126–135; 1985.Google Scholar
  7. 7.
    Downs, T.D.; Liebman, J. Statistical methods for vectorcardiographic directions. IEEE Trans Biomed Eng. BME-16:87–94; 1969.Google Scholar
  8. 8.
    Eyster, J.A.E.; Krashno, M.R.; Maaske, C.A.; Ulevich, M.J. The origin of the R and T potentials from the mammalian heart. Am J Physiol. 120:663–665; 1937.Google Scholar
  9. 9.
    Fischer, B. Referenzbereiche von 18 Blutwerten und die Bedeutung einiger Einflussgrossen auf Messwerte bei weiblichen Kaninchen. Z Versuchstierk 22:234–248; 1980.Google Scholar
  10. 10.
    Gabor, D.; Nelson, C.V. Determination of the resultant dipole of the heart from measurements on the body surface. J Appl Physics. 25:413–416; 1954.CrossRefGoogle Scholar
  11. 11.
    Geselowitz, D.B. On bioelectric potentials in an inhomogeneous volume conductor. Biophys J. 7:1–11; 1967.Google Scholar
  12. 12.
    Gulrajani, R.M.; Mailloux, G.E. A simulation study of the effects of torso inhomogeneities on electrocardiographic potentials using realistic heart and torso models. Circ Res. 52:45–56; 1983.PubMedGoogle Scholar
  13. 13.
    Horacek, B.M. Torso inhomogeneities. In: Zywitez, Chr.; Schneider, B. (eds). computer Applications on ECG and VCG Analysis, Amsterdam: North Holland 1973; pp. 23–33.Google Scholar
  14. 14.
    Horan, L.G.; Andreae, R.L.; Yoffee, H.F. The effect of intracavitary carbon dioxide on surface potentials in the intact canine chest. Am Heart J. 61:504–514; 1961.CrossRefPubMedGoogle Scholar
  15. 15.
    Ideker, R.E.; Bandura, J.P.; Cox, J.W., Jr.; Keller, F.W.; Mirvis, D.M.; Brody, D.A. Path and significance of heart vector migration during QRS and ST-T complexes of ectopic beats in isolated perfused rabbit hearts. Circ Res. 41:558–564; 1977.PubMedGoogle Scholar
  16. 16.
    Lepeschkin, E. Physiological influences on transfer factors between heart currents and body surface potentials. In: Nelson, C.V.; Geselowitz, D.B. (eds). Theoretical Basis of Electrocardiology, Oxford: Clarendon: 1975; pp. 135–161.Google Scholar
  17. 17.
    Mirvis, D.M. Comparison of isopotential surface mapping and dipole ranging methods for assessing equivalent cardiac generator properties. Cardiovasc Res. 14:360–368; 1980.PubMedGoogle Scholar
  18. 18.
    Mousesyan, M.A.; Mkrtchyen, L.N. On the normal electrocardiogram of the rabbit. Zh Eksp Klin Med. 4:73–79; 1964.Google Scholar
  19. 19.
    Nagata, Y. The influence of the inhomogeneities of electrical conductivity within the torso on the electrocardiogram as evaluated from the view point of the transfer impedance vector. Jap Heart J. 11: 489–505; 1970.PubMedGoogle Scholar
  20. 20.
    Nelson, C.V. Simple method for measuring heart vector of isolated animal hearts. Science. 133:1831–1832; 1961.PubMedGoogle Scholar
  21. 21.
    Nelson, C.V.; Waggoner, W.C.; Gastonguay, P.R. High-fidelity electrocardiograms of normal rabbits. Am J Physiol. 207:1104–1111; 1964.Google Scholar
  22. 22.
    Nelson, C.V.; Waggoner, W.C.; Gastonguay, P.R. The dipole moment of the isolated rabbit heart. Am J Physiol. 208:250–254; 1965.PubMedGoogle Scholar
  23. 23.
    Nelson, C.V.; Gastonguay, P.R.; Wilkinson, A.F.; Voukydis, P.C. A lead system for direction and magnitude of the heart vector. In: Hoffman, I., Hamby, R.I.; Glassman, E. (eds). Vectorcardiology 2. Amsterdam: North Holland: 1971; pp. 85–97.Google Scholar
  24. 24.
    Nelson, C.V.; Rand, P.W.; Angelakos, E.T.; Hugenholtz, P.G. Effect of intracardiac blood on the spatial vectorcardiogram. Part 1. Results in the dog. Circ Res. 31:95–104; 1972.PubMedGoogle Scholar
  25. 25.
    Nelson, C.V.; Hodgkin, B.C.; Voukydis, P.C. Determination of the locus of the heart vector from body surface measurements: Model experiments. J Electrocardiol. 8:135–146; 1975.PubMedGoogle Scholar
  26. 26.
    Nelson, C.V.; Hodgkin, B.C. Determine of magnitudes, directions, and locations of two independent dipoles in a circular conducting region from boundary potential measurements. IEEE Trans Biomed Eng. BME-28:817–823; 1981.Google Scholar
  27. 27.
    Nelson, C.V.; Hodgkin, B.C.; Rand, S. Determination of two dipoles in a spherical conductor from surface potential measurements. Proc. 10th Ann Northeast Bioeng. Conf, Hanover, NH, March 15–16; 1982.Google Scholar
  28. 28.
    Rand, P.W.; Nelson, C.V.; Lacombe, E.H.; Barker, N.D.; Pirone, L.A. Application of an isolated heart model to investigate blood-oxygen delivery. Am J Physiol. 237:H348-H352; 1979.PubMedGoogle Scholar
  29. 29.
    Rosenthal, A.; Restieaux, N.J.; Feig, S.A. Influence of acute variations in hematocrit on the QRS complex of the Frank electrocardiogram. Circulation. 44:456–465; 1971.PubMedGoogle Scholar
  30. 30.
    Rudy, Y.; Wood, R.; Plonsey, R.; Liebman, J. The effects of high lung conductivity on electrocardiographic potentials: Results from human subjects undergoing bronchopulmonary lavage. Circulation. 65:440–445; 1982.PubMedGoogle Scholar
  31. 31.
    Rush, S., Nelson, C.V. The effects of electrical inhomogeneity and anisotropy of thoracic tissues on the field of the heart. In: Nelson, C.V., Geselowitz, D.B. (eds). Theoretical Basis of Electrocardiology, Oxford: Clarendon: 1976; pp. 323–354.Google Scholar
  32. 32.
    Savard, P.; Mailloux, G.E.; Roberge, F.A.; Gulrajani, R.M.; Guardo, R. A simulation study of the single moving dipole representation of cardiac electrical activity. IEEE Trans Biomed Eng, BME-29: 700–707; 1982.Google Scholar
  33. 33.
    Szabuniewicz, M.; Hightower, D.; Kyzer, J.R. The electrocardiogram, vectorcardiogram, and spatiocardiogram in the rabbit. Can J Comp Med. 35:107–114; 1971.PubMedGoogle Scholar
  34. 34.
    Van Oosterum, A.; deBoer, R.W.; van Dan, R.Th. Intramural resistivity of cardiac tissues. Med Biol Eng Comput. 17:337–343; 1979.Google Scholar
  35. 35.
    Voukydis, P.C.; Angelakos, E.T.; Nelson, C.V. Electrical effects of a highly conductive mass inside the thorax. Am Heart J. 85:382–388; 1973.CrossRefGoogle Scholar

Copyright information

© Maxwell Pergamon Macmillan plc 1989

Authors and Affiliations

  • Clifford V. Nelson
    • 2
  • Brian C. Hodgkin
    • 1
  1. 1.Biomedical Research InstituteUniversity of Southern MainePortland
  2. 2.Research DepartmentMaine Medical CenterPortland

Personalised recommendations