See also

Afebrile Seizures
Supraventricular Tachycardia
Coma

Key points

1. An arrhythmia should be considered in all children with syncope 
2. Most paediatric syncope is vasovagal
3. A thorough history is the best strategy to determine the cause of  syncope and guide further investigation

Background

• Syncope is a brief and sudden loss of consciousness associated with loss of postural tone with spontaneous recovery
• Paediatric syncope is common, with about 15% of children experiencing an episode before the end of adolescence
• Most paediatric syncope is benign and has an autonomic cause (ie vasovagal or orthostatic)
• Syncope is less commonly caused by life-threatening cardiac conditions such as structural abnormalities and arrhythmia
• Neurological conditions such as seizure and migraine may mimic syncope

Assessment

Causes and Differential diagnoses

History

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:

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:

• lack of prodrome
• palpitations or chest pain
• exercise-induced syncope
• past cardiac history
• family history of early cardiac death, arrhythmia or sudden death

Examination

• Orthostatic heart rate and blood pressure measurements 
• Complete cardiac and neurological examination

Management

Investigations

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 ECG interpretation)

• A blood glucose level can be useful if the child is seen shortly after the event
• Obtain a full blood count if anaemia is suspected
• Consider pregnancy testing

Treatment

*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.

Consider consultation with a local paediatric team when

• Children with a suspicion of cardiac syncope on history, examination or ECG should be urgently referred to a paediatrician or cardiologist
• Children with recurrent vasovagal or orthostatic syncope that do not respond to non-pharmacological treatment could be referred to a paediatrician or cardiologist 
• Children with presentations suspicious for seizures should be referred to a paediatrician or neurologist

Consider transfer when

• Children that are persistently symptomatic when seen and/or requiring care beyond the level of comfort of the local hospital 
• Children with clustering of syncope with cardiac features

Consider discharge when

The most likely cause of syncope has been identified and follow up has been arranged 

Last updated August 2018