The Morphology of the Cardiac Conduction System

  1. Derek J. Chadwick Organizer and
  2. Jamie Goode
  1. Robert H. Anderson1 and
  2. Siew Yen Ho2

Published Online: 7 OCT 2008

DOI: 10.1002/0470868066.ch2

Development of the Cardiac Conduction System: Novartis Foundation Symposium 250

Development of the Cardiac Conduction System: Novartis Foundation Symposium 250

How to Cite

Anderson, R. H. and Ho, S. Y. (2003) The Morphology of the Cardiac Conduction System, in Development of the Cardiac Conduction System: Novartis Foundation Symposium 250 (eds D. J. Chadwick and J. Goode), John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/0470868066.ch2

Author Information

  1. 1

    Cardiac Unit, Institute of Child Health and Great Ormond Street Hospital for Children NHS Trust, University College London, 30 Guilford Street, London WC1N 1EH, UK

  2. 2

    Faculty of Medicine, Paediatrics, National Heart & Lung Institute, Royal Brompton Campus, Imperial College, Dovehouse Street, London SW3 6LY, UK

Publication History

  1. Published Online: 7 OCT 2008
  2. Published Print: 20 JUN 2003

Book Series:

  1. Novartis Foundation Symposia

Book Series Editors:

  1. Novartis Foundation

ISBN Information

Print ISBN: 9780470850350

Online ISBN: 9780470868065

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Summary

The system responsible for initiation and propagation of the heartbeat became understood within the 20th century. Thus, it was Tawara (in 1906) who clarified the arrangement of the specialized muscular axis responsible for atrioventricular conduction, while Keith & Flack (in 1907) published the first account of the sinus node. Tawara's findings provide robust anatomic criteria for distinction of postnatal conduction pathways. Such pathways should be composed of cells which are histologically discrete, which can be traced from section to section in the histological series, and which are insulated by fibrous sheaths from the adjacent working myocardium. The cells making up the sinus and atrioventricular nodes fulfil the first two of these criteria, whilst those making up the ventricular conduction pathways fulfil all three criteria. The sinus node is found subepicardially within the terminal groove. The atrioventricular node, surrounded by its zones of transitional cells, is at the apex of the triangle of Koch. The penetrating bundle is sandwiched between the fibrous and muscular parts of the ventricular septum, with the bundle branches descending on either side of the septum. Other than nodal remnants found within the tricuspid vestibule, there are no other histologically discrete tracts to be found within the atrial myocardium.