Does monitoring of cerebral oximetry using NIRS during head-up tilt test detect changes in cerebral tissue oxygenation in adults with unexplained syncope?
Absolute cerebral oximetry monitoring using NIRS during head-up tilt testing has clinical utility for investigating unexplained syncope, demonstrating that syncope occurs when SctO2 falls below 60%.
Progressive decrease in cerebral tissue oxygenation independent of mean-arterial pressure may precede spontaneous vasovagal reflex during tilt. Patients experience syncope when SctO2 falls below 60%. These data confirm clinical utility of absolute cerebral oximetry monitoring for syncope investigation. We applied NIRS to measure frontal cerebral tissue oxygen saturation (SctO2) during head-up tilt test (HUT) in patients with unexplained syncope. In 44 of 54 patients, HUT was diagnostic. In patients with syncope, a significant SctO2-decrease was observed. Different patterns of SctO2 can be detected.
Bachus et al. (Thu,) studied this question.