[Clinico-neurophysiological features of the course of the disease in patients with paroxysmal atrial fibrillation].

The subjects of the study were 32 patients with paroxysmal atrial fibrillation (AF) and 19 ':ealthy individuals using a clinical and neurophysiological method of toposelective mapping of electroencephalogram (EEG). EEG was done during the inter-attack, pre-attack, and post-attack periods, as well as during a paroxysm. During the inter-attack period, the patients had a lower beta-rhythm power vs. the healthy controls, while there were no significant differences between them in the power of alpha- and beta-activity. Before an attack, the patients had a significant increase in beta, alpha-, and theta-range power, reflecting the intensification of the activity of the metaencephalic reticular formation, thalamocortical, and hypothalamosepto-hyppocampal systems, respectively. During an AF paroxysm, the activity of the thalamocortical and reticular systems was lowered, while the activity of the hypothalamo-hyppocampal system further increased. After an attack, the activity of all the mentioned systems went down to the initial state of the "optimal" brain functioning after an excessive excitation. It is assumed that generalized one-way direction of EEG changes before an attack reflects tensed functioning of practically all activation systems, which increases the probability of a "breakdown" in a form of an AF paroxysm. The data of the study evidence a cyclic character of the disease and stresses an important role in AF pathogenesis played by disturbances associated with the functional condition of non-specific temporal-limbic and reticular brain structures, especially in patients without organic myocardial alterations.