Syncope in Pediatric

Syncope

A syncopal attack is brief, usually with sudden loss of consciousness and muscle tone caused by cerebral ischemia or inadequate oxygen or glucose to the brain.

Features

• It usually lasts only a few seconds

• The child limp and unresponsive

• Tonic—clonic movements can occur with prolonged unconsciousness

• The patient is back to normal on awakening

Cause

There are several causes, including:

• Vasovagal (fainting)

• Orthostatic or postural hypotension

• Cardiac

• structural (e.g. critical aortic stenosis, tetralogy of Fallot, atrial myxoma etc.)

• arrhythmia (e.g. prolonged QT, AV block, sick sinus syndrome)

• Respiratory (e.g. cough, hyperventilating, breath holding)

• Metabolic (e.g. anemia, hypoglycemia, hysteria etc.)

Management

A history of the surrounding events is important. Orthostatic hypotension usually occurs on standing suddenly. Vasovagal collapse is usually associated with environmental or emotional stresses. Structural cardiac lesion is more likely if the syncope is exertional. 

The patient should be examined for cardiac anomaly (e.g. murmur, heaves etc). Investigations should include an ECG to look for dysrythmias, short/abnormal PR interval (e.g. Wolff-Parkinson-White syndrome) or prolonged QT syndrome.

If unconsciousness lasts more than a few seconds and the patient is not fully awake immediately after the event, then consider seizures as a cause. The patient may need an EEG to clarify this issue. Hysterical syncope generally occurs in front of an audience, patients do not hurt themselves and there is associated moaning or nonrhythmical jerking.

Follow up

All patients who have unexplained syncope should be reviewed in outpatients.