17. Neurally Mediated Syncope
Published Online: 1 NOV 2012
Copyright © 2013 John Wiley & Sons, Ltd.
Bennett's Cardiac Arrhythmias: Practical Notes on Interpretation and Treatment, Eighth Edition
How to Cite
Bennett, D. H. (2013) Neurally Mediated Syncope, in Bennett's Cardiac Arrhythmias: Practical Notes on Interpretation and Treatment, Eighth Edition, John Wiley & Sons, Ltd, Oxford. doi: 10.1002/9781118432389.ch17
- Published Online: 1 NOV 2012
- Published Print: 14 JAN 2013
Print ISBN: 9780470674932
Online ISBN: 9781118432389
- Carotid sinus syndrome;
- Malignant vasovagal syndrome;
- Neurally mediated syncope;
- Postural orthostatic tachycardia syndrome (POTS);
- Tilt-table test;
- Vasovagal syndrome
Vasovagal and carotid sinus syndromes are due to abnormal autonomic nervous system reflexes that can cause syncope due to bradycardia and/or hypotension. The malignant vasovagal syndrome, also termed neurocardiogenic syncope, is characterised by recurrent, abrupt syncope when sitting or standing, and a positive tilt-table test that can be used to demonstrate the cardioinhibitory and/or vasodepressor elements of the syndrome. Pacing may prevent syncope when caused by the former element but will not influence symptoms if due to the latter. A generous intake of both water and salt can be effective in preventing symptoms.
The diagnosis of carotid sinus syndrome is made in patients who suffer from near-syncope or syncope in whom carotid sinus massage causes sinus arrest or complete AV block for 3 s or more.
‘Situational faints’ are triggered by a variety of factors such as sight of blood, venepuncture, pain, emotion or oppressive environment.