The anatomy and physiology of the sinoatrial node--a contemporary review

Pacing Clin Electrophysiol. 2010 Nov;33(11):1392-406. doi: 10.1111/j.1540-8159.2010.02838.x. Epub 2010 Oct 14.


The sinoatrial node is the primary pacemaker of the heart. Nodal dysfunction with aging, heart failure, atrial fibrillation, and even endurance athletic training can lead to a wide variety of pathological clinical syndromes. Recent work utilizing molecular markers to map the extent of the node, along with the delineation of a novel paranodal area intermediate in characteristics between the node and the surrounding atrial muscle, has shown that pacemaker tissue is more widely spread in the right atrium than previously appreciated. This can explain the phenomenon of a "wandering pacemaker" and concomitant changes in the P-wave morphology. Extensive knowledge now exists regarding the molecular architecture of the node (in particular, the expression of ion channels) and how this relates to pacemaking. This review is an up-to-date summary of the current state of our appreciation of the above topics.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Aging
  • Animals
  • Arrhythmias, Cardiac / physiopathology
  • Atrial Function, Right / physiology
  • Biological Clocks / physiology
  • Diabetes Mellitus, Type 2 / physiopathology
  • Dogs
  • Female
  • Gap Junctions / physiology
  • Heart Failure / physiopathology
  • Humans
  • Ion Channels / physiology
  • Mice
  • Physical Endurance / physiology
  • Rats
  • Sick Sinus Syndrome / genetics
  • Sick Sinus Syndrome / physiopathology
  • Sinoatrial Node / anatomy & histology*
  • Sinoatrial Node / physiology*


  • Ion Channels