Autonomic cardiac rhythm regulation in residents of Izhma district of the Komi Republic

Heart rate variability (HRV) indices were analyzed in 110 residents of the Izhma district of the Komi Republic (Izhma settlement, n=37; Sizyabsk settlement, n=33; Bakur settlement, n=18; Diyur settlement, n=22). Most HRV indices in the Izhma district residents were within normal range for moderate latitudes. Deviations from that range were observed for relative power values in the high- frequency (HF,%), index of activity of the regulatory systems, percentage of times successive cardio intervals were greater than the previous interval by more than 50 ms (pNN50), and standard deviation of normal cardio intervals (SDNN). After the assessment of collected data 47,7% of participants were labeled as healthy, prenosological states were diagnosed in 39,4% participants, premorbid states - in 9,2%, and 3,7% of participants were found to have failure of adaptation mechanisms. Statistically significant differences in HRV indices between residents of settlements in our study were attributed to differences in age between groups of participants, not the locations.