Current aspects of the basic concepts of the electrophysiology of the sinoatrial node.
Author: Pérez-Riera AR1, Barbosa-Barros R2, Daminello-Raimundo R3, de Abreu LC4, Nikus K5
Affiliation:
1Laboratório de Metodologia de Pesquisa e Escrita Científica, Faculdade de Medicina do ABC, Santo André, São Paulo, Brazil. Electronic address: riera@uol.com.br.
2Coronary Center of the Hospital de Messejana Dr. Carlos Alberto Studart Gomes, Fortaleza, Ceará, Brazil.
3Laboratório de Metodologia de Pesquisa e Escrita Científica, Faculdade de Medicina do ABC, Santo André, São Paulo, Brazil.
4Laboratório de Metodologia de Pesquisa e Escrita Científica, Faculdade de Medicina do ABC, Santo André, São Paulo, Brazil; Graduate Entry Medical School, University of Limerick, Limerick, Ireland.
5Heart Center, Tampere University Hospital and Faculty of Medicine and Health Technology, Tampere University, Finland. Electronic address: kjell.nikus@sydansairaala.fi.
Conference/Journal: J Electrocardiol.
Date published: 2019 Aug 19
Other:
Volume ID: 57 , Pages: 112-118 , Special Notes: doi: 10.1016/j.jelectrocard.2019.08.013. [Epub ahead of print] , Word Count: 157
Cardiac pacemaker cells, also named P-cells (pale cytoplasm, pacemaker, phylogenetically primitive), including cells of the sinoatrial node, are heterogeneous in size, morphology, and electrophysiological characteristics. The exact extent to which these cells differ electrophysiologically in the human heart is unclear, yet it is critical for the understanding of normal cellular function. In this review, we describe major ionic currents and Ca2+ clocks acting on Ca2+ release in the sarcoplasmic reticulum. We also explain the external regulation of the heart rate controlled by the two branches of the autonomic (involuntary) nervous system: the sympathetic and the parasympathetic nervous system. Vagal stimulus causes bradycardia, rapid and short-duration modulation, and controls rapid responses, and increases heart rate variability. A typical example is constituted by phasic or respiratory sinus arrhythmia, characterized by pronounced vagal activity, more frequent in children and young individuals.
Copyright © 2018 Elsevier Inc. All rights reserved.
KEYWORDS: Calcium clock; Ion channels; Sarcoplasmic reticulum; Sinus node
PMID: 31654967 DOI: 10.1016/j.jelectrocard.2019.08.013
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