Sophisticated architecture is required for the sinoatrial node to perform its normal pacemaker function.
The heart's pacemaker, the sinoatrial node, does not consist of a group of uniform sinoatrial node cells embedded in atrial muscle. Instead, it is a heterogeneous tissue with multiple cell types and a complex structure. Evidence suggests that from the periphery to the center of the sinoatrial node, there is a gradient in action potential shape, pacemaking, ionic current densities, connexin expression, Ca2+ handling, myofilament density, and cell size. This complexity may be necessary for the sinoatrial node to pacemake under diverse conditions, drive the more hyperpolarized atrial muscle, and resist proarrhythmic perturbations.
Boyett
Mark R
MR
School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom. m.r.boyett@leeds.ac.uk
Dobrzynski
Halina
H
Lancaster
Matthew K
MK
Jones
Sandra A
SA
Honjo
Haruo
H
Kodama
Itsuo
I
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D003199:Computer Systems; D006325:Heart Atria / Q000601:surgery; D006801:Humans; D008955:Models, Cardiovascular; D010138:Pacemaker, Artificial; D012849:Sinoatrial Node / Q000502:physiology* / Q000601:surgery*