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  • See also

    Afebrile Seizures
    Supraventricular Tachycardia
    Altered conscious state
    Basic Paediatric ECG interpretation

    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


    • 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 arrhythmias
    • Neurological conditions such as seizure and migraine may mimic syncope



    • Reflex syncope
      • Eg vasovagal syncope
      • Clear precipitating event, eg tiredness, hunger, heat, dehydration, emotion
    • Orthostatic hypotension
      • Within 2-3 minutes of assuming an upright position:
        • decrease in systolic blood pressure >20 mmHg
        • decrease in diastolic blood pressure of >10 mmHg
      • Causes include hypovolaemia, anaemia, electrolyte abnormalities, menorrhagia, medications
    • Postural orthostatic tachycardia syndrome (POTS) 

      • Daily symptoms of chronic orthostatic intolerance
      • Within 5-10 minutes of assuming an upright position:
        • HR increase >40 bpm
        • HR increase >30 bpm without postural hypotension
    • Breath-holding spells 


    • Brady/tachyarrhythmia
    • Long QT syndrome
    • Brugada syndrome
    • Catecholaminergic polymorphic ventricular tachycardia
    • Conduction disease eg Wolff-Parkinson-White syndrome
    • Structural abnormalities eg congenital heart disease, cardiomyopathies, myocarditis

    Differential diagnoses

    • Seizure
    • Migraine
    • Hypoglycaemia
    • Toxin exposure eg carbon monoxide, clonidine
    • Functional disorder
    • Narcolepsy



    The child’s medical history and description of the event, including any previous episodes, is essential in identifying the cause of syncope

    Key features to differentiate syncope from a seizure


    Autonomic syncope

    Cardiogenic syncope


    Precipitating events:
    Including preceding symptoms and the position in which episode occurred

    Sudden or prolonged standing, painful or emotional stimulus, palpitations

    Prodromal symptoms such as dizziness, weakness and visual changes

    During exercise

    Usually no prodrome, however may have chest pain or palpitations

    Past cardiac history

    Family history of early cardiac death, arrhythmia or sudden death

    Usually none

    Period of unconsciousness

    Usually seconds

    Usually seconds

    Usually more than a few seconds, up to minutes




    May be present

    Confusion on waking



    Marked for 20-30 mins

    Tonic-clonic movements, presence and timing

    Occasionally and brief particularly if unconsciousness is prolonged (syncopal seizure)

    Occasionally and brief particularly if unconsciousness is prolonged (syncopal seizure)

    Frequently present


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



    • 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)
    • BGL can be useful if the child is seen shortly after the event
    • FBE (if anaemia is suspected)
    • Consider pregnancy testing


    syncope diagram


    Children with frequent and/or problematic vasovagal or orthostatic syncope

    • Avoid usual triggers
    • Increase fluid and salt intake
    • Early recognition of prodromal symptoms

    Consider consultation with a local paediatric team when

    • Suspicion of cardiac syncope on history, examination or ECG. Urgently refer to a paediatrician or cardiologist
    • Children with recurrent vasovagal or orthostatic syncope that do not respond to non-pharmacological treatment. Refer to paediatrician or cardiologist
    • Children with presentations suspicious for seizures. Refer to paediatrician or neurologist

    Consider transfer when

    • Children are persistently symptomatic on assessment
    • Children with clustering of syncope with cardiac features
    • Requiring care beyond the level of comfort of the local hospital

    For emergency advice and paediatric or neonatal ICU transfers, see Retrieval Services

    Consider discharge when

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

    Last updated November 2023


  • Reference List

    1. Hurst D, Hirsh DA, Oster ME, et al. Syncope in the Pediatric Emergency Department - Can We Predict Cardiac Disease Based on History Alone? J Emerg Med 2015; 49(1): 1-7
    2. Friedman KG, Alexander ME. Chest pain and syncope in children: a practical approach to the diagnosis of cardiac disease. J Pediatr 2013; 163(3): 896-901 e1-3
    3. UpToDate. Reflex syncope in adults and adolescents: Treatment. (viewed December 2022)
    4. Ritter S, Tani LY, Etheridge SP, Williams RV, Craig JE, Minich LL. What is the yield of screening echocardiography in pediatric syncope? Pediatrics 2000; 105(5): E58