© 2000 by European Society of Cardiology
Copyright © 2000, European Society of Cardiology
The sinoatrial node, a heterogeneous pacemaker structure
aSchool of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, UK
bResearch Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan
* Corresponding author. Tel.: +44-113-233-4298; fax: +44-113-233-4224 m.r.boyett{at}leeds.ac.uk
This article focuses on the regional heterogeneity of the mammalian sinoatrial (SA) node in terms of cell morphology, pacemaker activity, action potential configuration and conduction, densities of ionic currents (iNa, iCa,L, ito, iK,r, iK,s and if), expression of gap junction proteins (Cx40, Cx43 and Cx45), autonomic regulation, and ageing. Experimental studies on the single SA node cell to the whole animal are reviewed. The heterogeneity is considered in terms of the gradient model of the SA node, in which there is gradual change in the intrinsic properties of SA node cells from periphery to centre, and the alternative mosaic model, in which there is a variable mix of atrial and SA node cells from periphery to centre. The heterogeneity is important for the dependable functioning of the SA node as the pacemaker for the heart, because (i) via multiple mechanisms, it allows the SA node to drive the surrounding atrial muscle without being suppressed electrotonically; (ii) via an action potential duration gradient and a conduction block zone, it promotes antegrade propagation of excitation from the SA node to the right atrium and prevents reentry of excitation; and (iii) via pacemaker shift, it allows pacemaking to continue under diverse pathophysiological circumstances.
KEYWORDS Gap junctions; Ion channels; Sinus node
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
Y. Kurata, H. Matsuda, I. Hisatome, and T. Shibamoto Regional Difference in Dynamical Property of Sinoatrial Node Pacemaking: Role of Na+ Channel Current Biophys. J., July 15, 2008; 95(2): 951 - 977. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. L. Bakker, B. J. Boukens, M. T.M. Mommersteeg, J. F. Brons, V. Wakker, A. F.M. Moorman, and V. M. Christoffels Transcription Factor Tbx3 Is Required for the Specification of the Atrioventricular Conduction System Circ. Res., June 6, 2008; 102(11): 1340 - 1349. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Fukuzaki, T. Sato, T. Miki, S. Seino, and H. Nakaya Role of sarcolemmal ATP-sensitive K+ channels in the regulation of sinoatrial node automaticity: an evaluation using Kir6.2-deficient mice J. Physiol., June 1, 2008; 586(11): 2767 - 2778. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Lignon, Z. Bichler, B. Hivert, F. E. Gannier, P. Cosnay, J. A. del Rio, D. Migliore-Samour, and C. O. Malecot Altered heart rate control in transgenic mice carrying the KCNJ6 gene of the human chromosome 21 Physiol Genomics, April 21, 2008; 33(2): 230 - 239. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. M. Vinogradova, S. Sirenko, A. E. Lyashkov, A. Younes, Y. Li, W. Zhu, D. Yang, A. M. Ruknudin, H. Spurgeon, and E. G. Lakatta Constitutive Phosphodiesterase Activity Restricts Spontaneous Beating Rate of Cardiac Pacemaker Cells by Suppressing Local Ca2+ Releases Circ. Res., April 11, 2008; 102(7): 761 - 769. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. Jones, M. Yamamoto, J. O. Tellez, R. Billeter, M. R. Boyett, H. Honjo, and M. K. Lancaster Distinguishing Properties of Cells From the Myocardial Sleeves of the Pulmonary Veins: A Comparison of Normal and Abnormal Pacemakers Circ Arrhythmia Electrophysiol, April 1, 2008; 1(1): 39 - 48. [Abstract] [Full Text] [PDF] |
||||




