The timely provided and precise diagnostic of the syncopal states as well as their causal therapy is a main subject of many medical branches interest within last time. Our work was concentrated on a vasovagal neurocardiogenic syncope. The definition of the vegetative nervous tonus participation on its development by a method of evaluation of the heart rate variability as well as the review of a possibility to the application of quantification these results to a prediction of vasovagal reaction, respective of its malignant variant, was the main aim of our effort. Our results enable a conclusion, that the observation of aquiet autonomic nervous tonus does not represent a contribution to a differential diagnostics of syncope of uncleared etiology with a suspicion on vasovagalous neurocardiogenous syncope, because the basal vagal tonus does not allow the forecast of head upright tilt table testing results as well as determination of the type of respectively provocated vasovagal neurocardiogenic syncope. However, a correlation between an actual reactive vageous tonus surveyed by the SD index for patients with vasovagal neurocardiogenic syncope of the type I and IIa in comparison with healthy persons, was found out. It allows to draw a conclusion, that the vasovagal neurocardiogenic syncope is not homogeneous nosological unit, what results in efforts to it's more detailed classification.

Keywords: Adult; Autonomic Nervous System /physiopathology/; Female; Heart Rate; Humans; Male; Syncope, Vasovagal /physiopathology/; Tilt-Table Test