Medical and biological engineering

, Volume 13, Issue 6, pp 825–830 | Cite as

Computer simulation of notches on h.f. e.c.g. and an interpretation of their origin

  • D. Sapoznikov
  • J. Weinman
Article

Abstract

A computer simulation of the high-fidelity e.c.g. was performed to explain the origin of notches and slurs appearing on such recordings. The simulation demonstrates that the superimposition of separate QRS-like waveforms leads to the appearance of notches, and also points to some possible pitfalls in their interpretation. Variations observed in the shape of the notches due to respiration indicate clearly that it is misleading, for diagnostic purposes, to count notches and disregard slurs, or to attach diagnostic importance to the amplitudes or the shapes of the notches, if they appear on different phases of the QRS complex.

Keywords

Simulation High fidelity e.c.g. Respiration 

Sommaire

On a effectué la simulation par ordinateur d'un e.c.g. à haute fidélité, afin d'expliquer l'origine des encoches et des mâchures produites par de tels enregistrements. La simulation démontre que la superposition d'ondes de forme QRS séparées mène à l'apparition d'encoches et indique aussi la possibilité d'erreurs dans leur interprétation. Les variations de forme des encoches, observées, dûes á la respiration indiquent nettement que pour les diagnostics, compter les encoches et ignorer les mâchures ou attacher de l'importance diagnostique à l'amplitude et à la forme des encoches peuvent induire en erreur si celles-ci se présentent à différentes phases du complexe QRS.

Zusammenfassung

Die Rechnersimulation des HiFi-EKGs wurde vorgenommen, um den Ursprung von Kerben und Undeutlichkeiten zur erklären, die in solchen Aufzeichnungen auftraten. Die Simulation zeigt, daß die Überlagerung von getrennten QRS-ähnlichen Wellenformen zum Auftreten von Kerben führt, und weist auf gewisse mögliche Irrtümer in ihrer Interpretation hin. Durch Atmung ausgelöste Veränderungen in der Kerbenform zeigen klar, daß es zu diagnostischen Zwecken irreführen ist, die Kerben zu zählen und die Unklarheiten unbeachtet zu lassen oder den Amplituden oder Formen der Kerben diagnostische Bedeutung beizumessen, wenn sie in verschiedenen Phasen des QRS-Komplexes auftauchen.

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References

  1. Buchthal, F. andRosenfalck, A. (1966) Evoked action potentials and conduction velocity in human sensory nerves.Brain Res.,3, 1–122.CrossRefGoogle Scholar
  2. Durrer, D., Van Dam, R. Th., Freud, G. E., Janse, M. J., Meijler, F. L. andArzbaecher, H. (1970) Total excitation of the isolated heart.Circulation,41, 899–912.Google Scholar
  3. Einthoven, W., Fahr, G. andde Waart, A. (1950) On the direction and manifest size of the variations of potential in the human heart and on the influence of the position of the heart on the form of the electrocardiogram.Am. Heart J.,40, 163–194. (Translated fromHoff, H. E. andSekelj, P. (1913)Arch. Physiol.,150, 275–315).CrossRefGoogle Scholar
  4. Gasser, H. S. andErlanger, J. (1972) The role played by the sizes of the consistent fibers of a nerve trunk in determining the form of its action potential wave.Am. J. Physiol.,80, 522–547.Google Scholar
  5. Gasser, H. S. (1928) The relation of the slope of the action potential of nerve to conduction velocity.Ibid.,,84, 964–711.Google Scholar
  6. Lamb, L. E. (1957) The effects of respiration on the electrocardiogram in relation to differences in right and left ventricular stroke volume.Am. Heart J.,54, 342–351.CrossRefGoogle Scholar
  7. Langner, P. M., Gaselowitz, D. B. andBriller, S. A. (1973) Wide band recording of the electrocardiogram and coronary heart disease.Am. Heart J.,86, 308–317.CrossRefGoogle Scholar
  8. Magora, A. andGonen, B. (1972) Clinical evaluation of the analysis of the shape of electromyographic spike.Electromyography,12, 255–265.Google Scholar
  9. Raunio, H. (1970) Initial and terminal notching of the QRS complex in the e.c.g. Academic Dissertation, University of Helsinki Faculty of Medicine.Google Scholar
  10. Raunio, H. andAnttonen, V. M. (1972) Initial and terminal notching of the QRS complex in the conventional electrocardiogram.Am. Heart J.,83, 717–719.CrossRefGoogle Scholar
  11. Reynolds, E. W., Muller, B. F., Captain, M. C., Anderson, G. J. andMuller, B. T. (1967) High frequency components in the electrocardiogram. A comparative study of normals and patients with myocardial disease.Circulation,35, 195–206.Google Scholar
  12. Rushton, W. A. M. (1951) A theory of the effects of fibre size in medullated nerve.J. Physiol.,115, 101–122.Google Scholar
  13. Sayers, B. McA. (1967) Computers and computing methods: The engineers viewpoint.Proc. Roy. Soc. Med.,60, 756–759.Google Scholar
  14. Uijen, G. J. H. andVendrik, A. J. H. (1973) The reproducibility of high frequency electrocardiograms.Digest of 10th Int. Conf. Med. & Biol. Eng., Dresden, 192.Google Scholar
  15. Weinman, J. andSapoznikov, D. (1969) The influence of slow blood volume waves on the shape of the dicrotic complex.IEEE Trans.,BME-16, 54–58.Google Scholar

Copyright information

© International Federation for Medical & Biological Engineering 1975

Authors and Affiliations

  • D. Sapoznikov
    • 1
  • J. Weinman
    • 1
  1. 1.Rogoff Laboratory for Biomedical EngineeringThe Hebrew University, Hadassah Medical SchoolJerusalemIsrael

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