Insufficient cerebral perfusion |
Transient raised intracranial pressure |
eg, hydrocephalic attack due to papilloma of the third ventricle |
Transient isolated cerebral arterial hypotension |
eg, G-LOC*, vertebra-basilar insufficiency, adolescent stretch syncope |
Transient systemic arterial hypotension with |
Reduced cardiac output |
Reduced stroke volume (eg, from reduced venous return, tachycardia) |
eg, hypovolaemia, forced expiration (Valsalva, expiratory apnoea), pulseless ventricular tachycardia, ventricular fibrillation |
Bradycardia |
eg, heart block |
Asystole |
eg, cardioinhibitory neurally mediated syncope/reflex asystolic syncope (reflex anoxic seizures) |
Reduced vascular resistance |
eg, septicaemia, anaphylaxis |
Reduced cardiac output and vascular resistance |
eg, vasodepressor and mixed neurally mediated syncope |
Hypoxaemic cerebral perfusion |
eg, acute left to right shunts; anaesthetic, aviation, diving, mountaineering accidents with transient exposure to hypoxia |
Hypoxaemic and insufficient cerebral perfusion |
eg, expiratory apnoea syncope (blue breath-holding) |
Hypoxaemic and/or insufficient cerebral perfusion, not otherwise specified |
Bold face refers to those relevant to paediatric practice.
↵* G-LOC, loss of consciousness associated with extreme gravitational force.