Аннотация:Objective : to study baseline autonomic tone and autonomic responsiveness in patients with neuroreflectory syncopal states (NSS) during a passive orthotest in orthostatic and clinostatic phases. Subjects and methods . A study group comprised 40 patients with NSS, a comparative group included 57 patients with panic attacks (PA); a control group consisted of 22 subjects without the above conditions. Cardiac rhythm variability was estimated applying a Neuron-spectrum device. Results . During the orthotest, the patients with NSS showed inadequate activity of the sympathetic nervous system as compared with the patients with PA and the control group. At the same time, the clinostatic test revealed that the indicators restored to the normal values in patients with NSS, unlike in those with PA.
