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Related to sinoatrial: sinoatrial block


pertaining to the sinus venosus and the atrium of the heart.

sin·u·a·tri·al (S-A, SA),

Relating to the sinus venosus and the right atrium of the heart.
Synonym(s): sinoatrial


/si·no·atri·al/ (si″no-a´tre-al) pertaining to the sinus venosus and the atrium of the heart.


Of or relating to the sinoatrial node: a sinoatrial heart block.

sinoatrial (SA)

Etymology: L sinus, hollow, atrium, hall
pertaining to the sinus node and atrium. Also called sinoauricular.


(SA) (sin'yū-ā'trē-ăl)
Relating to the sinus venosus of the embryo, or the sinus of the venae cavae of the mature heart, and the right atrium.
Synonym(s): sinoatrial.

sinoatrial (SA) node (sī´nōā´trēəl),

n a cluster of hundreds of cells located in the right atrial wall of the heart near the opening of the superior vena cava. It constitutes a knot of modified heart muscle that generates impulses, which travel swiftly throughout the muscle fibers of both atria, causing them to contract.


pertaining to the sinus venosus and the atrium of the heart or to the sinoatrial node; abbreviated S-A, SA.

sinoatrial block
an absence of a discharge from the sinoatrial node. The heart is regular unless there is an underlying atrial arrhythmia. Considered to be within the limits of normality provided it disappears with exercise.
sinoatrial node
a collection of atypical muscle fibers and nerve endings in the wall of the right atrium, adjacent to the sulcus terminalis, where the rhythm of cardiac contraction is usually established; therefore also referred to as the pacemaker of the heart. Called also sinoatrial bundle, Keith's node, Keith-Flack node.
References in periodicals archive ?
5) The sinoatrial (SA) nodal branch arises from the RCA in most patients (60%) and courses posteriorly.
This occurs when the activity of the heart's pacemaker, the sinoatrial node, is impaired.
7) RSA is the natural cycle of arrhythmia that occurs through the influence of breathing on the flow of sympathetic and vagus impulses to the sinoatrial node (http://biomedical.
Conduction disturbances like prolongation of the PQ interval and the widening of the QRS complex begin at serum magnesium concentrations of 3 to 4 mmol/l and proceed to sinoatrial or atrioventricular block at 6 mmol/l (14).
In the healthy human heart the sinoatrial node is richly innervated by the parasympathetic and sympathetic nervous systems.
Moreover, the interplay of sympathetic and parasympathetic (vagal) outputs of the central autonomic network at the sinoatrial node producing this complex beat-to-beat variability is characteristic of a healthy, adaptive organism (12).
In AF, the atria of the heart are stimulated by abnormal electrical impulses from the sinoatrial node and malfunctioning atrial tissue, resulting in an irregular and disorganized heart beat.
The ECGs of all 4 patients with CCC showed bradycardia, including sinoatrial block (SAB) in 2 patients, and grade III atrioventricular block (AVB) in 2 patients.
What in the human heart is the purpose of the sinoatrial node?
This cardiac cycle is regulated by nerve impulses, generated by the heart's internal pacemaker called the sinoatrial node (SA node), a small bundle of specialized cells located in the right atrium.
With regard to effects on cardiac rhythm, the cells of the sinoatrial (SA) node depolarize spontaneously, generating action potentials at a faster rate than other cardiac muscle cells, thus making this node the natural pacemaker of the heart (Seeley, Stephens, and Tate, 2003).