CEREBRAL OXYGENATION IN CHILDREN WITH SYNCOPE DURING HEAD-UPRIGHT TILT TEST

The pathophysiology of neurocardiogenic syncope remains incompletely k nown. In this entity, besides abnormal systemic hemodynamic regulation , potential cerebral circulatory abnormalities have been reported. In this setting, cerebral saturation assessment could detect cerebral blo od flow changes and estimate the sufficiency of brain oxygenation duri ng the event. A head-upright tilt test was performed in 25 children ag ed between 6 and 16 years. In addition to the standard protocol, cereb ral oxygen saturation was determined noninvasively by means of a near- infrared spectrophotometry device, In the 19 children with a positive tilt test, significant impairment of cerebral saturation was detected both at the start of the patient's complaints (without hemodynamic mod ifications) and during syncope. Our results support the hypothesis of the presence of abnormal cerebral hemodynamic autoregulation in childr en with neurocardiogenic syncope.