Sinoatrial node

The sinoatrial node (also known as the sinuatrial node, SA node or sinus node) is an oval shaped region of special cardiac muscle in the upper back wall of the right atrium made up of cells known as pacemaker cells. The sinus node is approximately 15 mm long, 3 mm wide, and 1 mm thick, located directly below and to the side of the superior vena cava. These cells can produce an electrical impulse known as a cardiac action potential that travels through the electrical conduction system of the heart, causing it to contract. In a healthy heart, the SA node continuously produces action potentials, setting the rhythm of the heart (sinus rhythm), and so is known as the heart's natural pacemaker. The rate of action potentials produced (and therefore the heart rate) is influenced by the nerves that supply it. The sinoatrial node is an oval-shaped structure that is approximately 15 mm long, 3 mm wide, and 1 mm thick, located directly below and to the side of the superior vena cava. The size can vary but is usually between 10-30 mm long, 5–7 mm wide, and 1–2 mm deep. The SA node is located in the wall (epicardium) of the right atrium, laterally to the entrance of the superior vena cava in a region called the sinus venarum (hence sino- + atrial). It is positioned roughly between a groove called the crista terminalis located on the internal surface of the heart and the corresponding sulcus terminalis, on the external surface. These grooves run between the entrance of the superior vena cava and the inferior vena cava. The cells of the SA node are spread out within a mesh of connective tissue, containing nerves, blood vessels, collagen and fat. Immediately surrounding the SA node cells are paranodal cells. These cells have structures intermediate between that of the SA node cells and the rest of the atrium. The connective tissue, along with the paranodal cells, insulate the SA node from the rest of the atrium, preventing the electrical activity of the atrial cells from affecting the SA node cells.

An integrated heart-torso electromechanical model for the simulation of electrophysiological outputs accounting for myocardial deformation

Alfio Quarteroni, Francesco Regazzoni

When generating in-silico clinical electrophysiological outputs, such as electrocardiograms (ECGs) and body surface potential maps (BSPMs), mathematical models have relied on single physics, i.e. of the cardiac electrophysiology (EP), neglecting the role o ...

Elsevier Science Sa2024

Correlation between conduction velocity and frequency analysis in patients with atrial fibrillation using high-density charge mapping

Jean-Marc Vesin, Lam Dang

Spectral analysis of atrial signals has been used to identify regions of interest in atrial fibrillation (AF). However, the relationship to the atrial substrate is unclear. In this study, we compare regions with dominant frequency (DF), simultaneously dete ...

SPRINGER HEIDELBERG2022

An integrated heart-torso electromechanical model for the simulation of electrophysiological outputs accounting for myocardial deformation

Active force generation contributes to the complexity of spontaneous activity and to the response to stretch of murine cardiomyocyte cultures

Correlation between conduction velocity and frequency analysis in patients with atrial fibrillation using high-density charge mapping

An integrated heart-torso electromechanical model for the simulation of electrophysiological outputs accounting for myocardial deformation

Correlation between conduction velocity and frequency analysis in patients with atrial fibrillation using high-density charge mapping

Active force generation contributes to the complexity of spontaneous activity and to the response to stretch of murine cardiomyocyte cultures