Onset of sweating depends on the type of reflex syncope

Reflex syncope is classified based on the efferent autonomic system as vasodepressant type, cardioinhibitory type and mixed type. We employed quantitative sweat testing to assess differences in sudomotor sympathetic activity in relation to the type of reflex syncope. In cardioinhibitory type sweating started in 7/9 patients after and in vasodepressor type in 11/12 patients before syncope. In mixed type sweating in 20 patients started before and in 10 after syncope. The onset of sweating correlated significantly with the onset of syncope symptoms. These results possibly reflect different onsets of emotional sweating.