Natalie Chandler and Oleg Aslanidi equally contributed to this work.
Computer Three-Dimensional Anatomical Reconstruction of the Human Sinus Node and a Novel Paranodal Area†
Article first published online: 28 APR 2011
Copyright © 2011 Wiley-Liss, Inc.
The Anatomical Record
Volume 294, Issue 6, pages 970–979, June 2011
How to Cite
Chandler, N., Aslanidi, O., Buckley, D., Inada, S., Birchall, S., Atkinson, A., Kirk, D., Monfredi, O., Molenaar, P., Anderson, R., Sharma, V., Sigg, D., Zhang, H., Boyett, M. and Dobrzynski, H. (2011), Computer Three-Dimensional Anatomical Reconstruction of the Human Sinus Node and a Novel Paranodal Area. Anat Rec, 294: 970–979. doi: 10.1002/ar.21379
Abbreviations used: AM = Atrial muscle; ANP = Atrial natriuretic peptide; Ao = Aorta; Cx40, Cx43 = Connexin 40 and 43; 3D = Three-dimensional; DT-MRI = Diffusion tensor magnetic resonance imaging; HCN4 = Ion channel responsible for hyperpolarization-activated or ‘funny’ current, If; IVC = Inferior vena cava; Kir2.1 = Ion channel responsible for background inward rectifier K+ current, IK1; Kir6.2 = Ion channel responsible for ATP-sensitive K+ current, IKATP; Kv1.4 = Ion channel responsible for transient outward K+ current, Ito; LAA = Left atrial appendage; MiRP2 = Accessory protein for K+ channels; N av1.5, Navβ1 = Na+ channel responsible for inward Na+ current, INa; PA = Pulmonary artery; PV = Pulmonary vein; RA = Right atrium; RAA = Right atrial appendage; RV = Right ventricle; SCV = Superior caval vein; SK2 = Ion channel responsible for Ca2+-activated K+ current, IKCa; TASK1 = Twin-pore domain K+ channel; Tbx3 = Transcription factor; TC = Terminal crest.
- Issue published online: 20 MAY 2011
- Article first published online: 28 APR 2011
- Manuscript Accepted: 27 JAN 2011
- Manuscript Received: 19 JUN 2010
- Medtronic Inc
- sinus node;
- 3D anatomical model;
We have previously shown in rabbit that the pacemaker of the heart (the sinus node) is widespread and matches the wide distribution of the leading pacemaker site within the right atrium. There is, however, uncertainty about the precise location of the pacemaker in human heart, and its spatial relationships with the surrounding right atrial muscle. Therefore, the aim of the current study was to investigate the distribution of the sinus node tissue in a series of healthy human hearts and, for one of the hearts to construct a computer three-dimensional anatomical model of the sinus node, including the likely orientation of myocytes. A combination of experimental techniques—diffusion tensor magnetic resonance imaging (DT-MRI), histology, immunohistochemistry, image processing and computer modelling—was used. Our data show that the sinus node was larger than in previous studies and, most importantly, we identified a previously unknown area running alongside the sinus node (the “paranodal area”), which is even more extensive than the sinus node. This area possesses properties of both nodal and atrial tissues and may have a role in pacemaking. For example, it could explain the wide spread distribution of the leading pacemaker site in human right atrium, a phenomenon known as the wandering pacemaker observed in clinics. In summary, a novel 3D anatomical reconstruction presents a new picture of the distribution of nodal cells within the human right atrium. Anat Rec, , 2011. © 2011 Wiley-Liss, Inc.