Neurophysiological Markers of Stress within a Recovery Period after Acute Complications of Cardiovascular Diseases

In the course of rehabilitation in a sanatorium, we provided polygraphic examination of a group of 14 men who endured myocardial infarction or stroke one to three months ago. Fourteen men of a comparable age (55 years, on average), healthy from the aspect of diseases of the cardiovascular system, served as the control group. Examination was performed using a flexible data acquisition and feedback platform «Nexus-10 Mark II» (the Netherlands) allowing us to simultaneously record ECG, EMG, EEG, respiratory movements, pulse blood filling, skin temperature, electrodermal resistance, and a few other indices. It was found that patients suffering from complications of pathologies of the cardiovascular system were characterized by a significant increase in the electrodermal conductivity, clearly expressed tachypnea, and some trends toward tachycardia and decrease in the skin temperature. According to indices of the heart rate variability (HRV), the mean value of the Bayevskii stress index in patients was about three times higher than the analogous value in the control group, while the total power of the HRV spectrum was dramatically lower. The amplitude of tonic EMG activity recorded from mm. trapezii in the resting state considerably exceeded the respective value in control subjects. The amplitude of 8-13 Hz EEG oscillations in the Cz lead in patients was somewhat lower than in the control group, and increase in this index in the test with closing of the eyes in these subjects was manifested much slightly than in the control. Parallel recording of physiological (first of all, neurophysiological) indices allows researchers to effectively identify objective markers of the stress state developed after complications of diseases of the cardiovascular system; the respective data can be used in the curative procedures with the control of functions of the organism using a feedback technology by the parameters of activity of the functional systems (biofeedback control).