The Oldest, Toughest Cells in the Heart

  1. Derek J. Chadwick Organizer and
  2. Jamie Goode
  1. Robert P. Thompson,
  2. Maria Reckova,
  3. Angela de Almeida,
  4. Michael R. Bigelow,
  5. Chiffvon P. Stanley,
  6. Joshua B. Spruill,
  7. Thomas T. Trusk and
  8. David Sedmera

Published Online: 7 OCT 2008

DOI: 10.1002/0470868066.ch10

Development of the Cardiac Conduction System: Novartis Foundation Symposium 250

Development of the Cardiac Conduction System: Novartis Foundation Symposium 250

How to Cite

Thompson, R. P., Reckova, M., de Almeida, A., Bigelow, M. R., Stanley, C. P., Spruill, J. B., Trusk, T. T. and Sedmera, D. (2003) The Oldest, Toughest Cells in the Heart, 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.ch10

Author Information

  1. Department of Cell Biology and Anatomy, Cardiovascular Developmental Biology Center, Medical University of South Carolina, Charleston, SC 29425, USA

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



We review here the evolution and development of the earliest components of the cardiac pacemaking and conduction system (PCS) and the turnover or persistence of such cells into old age in the adult vertebrate heart. Heart rate is paced by upstream foci of cardiac muscle near the future sinoatrial junction even before contraction begins. As the tubular heart loops, directional blood flow is maintained through coordinated sphincter function in the forming atrioventricular (AV) canal and outflow segments. Propagation of initially peristaltoid contraction along and between these segments appears to be influenced by physical conditioning and orientation of inner muscle layers as well as by their slow relaxation; all characteristic of definitive conduction tissue. As classical elements of the mature conduction system emerge, such inner ‘contour fibres’ maintain muscular and electrical continuity between atrial and ventricular compartments. Elements of such primordial architecture are visible also in histological and optical–electrical study of fish and frog hearts. In the maturing chick heart, cells within core conducting tissues retain early thymidine labels from the tubular heart stage into adult life, dividing only slowly, if at all. Preliminary evidence from mammals suggest similar function and kinetics for these ‘oldest, toughest’ cells in the hearts of all vertebrates.