In this section
Afebrile Seizures guideline
Supraventricular Tachycardia guideline
Causes and Differential diagnoses
Vasovagal syncope (also called neurocardiogenic)
Postural orthostatic tachycardia syndrome
Long QT syndrome
Structural abnormalities (e.g. aortic stenosis, hypertrophic cardiomyopathy)
Toxic exposure (e.g. carbon monoxide, clonidine)
The child’s medical history and description of the event, including any previous episodes, is essential in identifying the cause of syncope.
Key features and useful features to differentiate from a seizure:
(including cardiac and autonomic causes)
Including preceding symptoms and the position in which episode occurred
Sudden or prolonged standing, painful or emotional stimulus, palpitations
Period of unconsciousness
Usually more than a few seconds, up to minute
May be present
Confusion on waking
Marked for 20-30 mins
Tonic-clonic movements, presence and timing
Occasionally & brief particularly if unconsciousness is prolonged (syncopal seizure)
Vasovagal syncope is typically preceded by a painful or emotional stimulus and prodromal symptoms such as dizziness, weakness and visual changes.
Red flags for potential cardiac aetiology are:
An ECG should be obtained in all children at least once. May not be required if
done previously and there is no additional concern. (see
*There may be brief tonic-clonic movements with vasovagal syncope
Children with frequent and/or problematic vasovagal or orthostatic syncope often achieve symptom control by avoiding usual triggers and increasing their fluid and salt intake.
The most likely cause of syncope has been identified and follow up has been arranged.
Last updated August 2018