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Respiratory sinus arrhythmia (RSA) is frequently used as a noninvasive method for investigating vagal tone, in physiological, behavioral, and several clinical studies. [ 16 ] [ 17 ] [ 18 ] This can be done using electrocardiography (ECG) recording, [ 19 ] although other methods are also being developed that take advantage of the interactions ...
Sinus arrhythmia is a commonly encountered variation of normal sinus rhythm. Sinus arrhythmia characteristically presents with an irregular rate in which the variation in the R-R interval is more than 0.12 seconds (120 milliseconds). Additionally, P waves are typically mono-form and in a pattern consistent with atrial activation originating ...
[18] [19] The main mechanism by which the parasympathetic nervous system acts on vascular and cardiac control is the so-called respiratory sinus arrhythmia (RSA). RSA is described as the physiological and rhythmical fluctuation of heart rate at the respiration frequency, characterized by heart rate increase during inspiration and decrease ...
A slow rhythm (less than 60 beats/min) is labelled bradycardia. This may be caused by a slowed signal from the sinus node (sinus bradycardia), by a pause in the normal activity of the sinus node (sinus arrest), or by blocking of the electrical impulse on its way from the atria to the ventricles (AV block or heart block).
Respiratory arrhythmia (or respiratory sinus arrhythmia). [39] [40] This heart rate variation is directly caused by the central respiratory rhythm, faithfully tracks the respiratory rate across a range of frequencies and is a major cause of heart rate variability in humans (Cooper HE, Clutton-Brock TH & Parkes MJ (2004). Contribution of the ...
The Bainbridge reflex may also contribute to respiratory sinus arrhythmia as intrathoracic pressure decreases during inspiration causing increased venous return. [3] [4] The reflex is named after Francis Arthur Bainbridge, an English physiologist. The Bainbridge reflex was one of the first neural cardiovascular reflexes to be described and ...
The cardiovascular centre, or cardiovascular center, is part of the medulla oblongata of the brainstem. [1] [2] Normally, the heart beats without nervous control.In some situations, such as exercise, and major trauma, the cardiovascular centre is responsible for altering heart rate.
Non-respiratory causes of sinus arrhythmia include sinus pause, sinus arrest, and sinoatrial exit block. Sinus pause and arrest involve slowing or arresting of automatic impulse generation from the sinus node. This can lead to asystole or cardiac arrest if ventricular escape rhythms do not create backup sources of cardiac action potentials. [2]