Cardiovascular response to whole-body cold exposure in humans with different initial autonomic tone

Relevance. Cold exposure increases sympathetic activity and blood pressure. It can also promote intensification of hypertension symptoms its progress in winter. However, the mechanisms this phenomenon are poorly understood. Intention: To determine dynamics cardiovascular parameters young people with different initial autonomic regulation heart rate during experimental general cold exposure. Methodology. 30 healthy male volunteers aged 18–20 years were examined. In accordance type rate, all subjects divided into 3 groups as follows: predominance vagotonia (Group I, n = 9), optimal – normotonia II, 14), sympathicotonia III, 7). The experiment included three stages: rest at a temperature (+20 0C); to (–20 0C) for 10 minutes; warming body 0C). variability (HRV) was recorded each stage study using portable complex “Varicard 2.8” (Russia). At same time, pressure ear canal recorded. Results Discussion . Moderate short-term air cooling causes generally temporary reactions central hemodynamics (increase pressure) indicators total HRV power an increase parasympathetic activity. Baseline dynamic values stress index Group III significantly higher than Groups I II. During cooling, individuals from 4 times lower, 1.5 lower before cooling. baroreflex less pronounced (slightly decreased HRV) along significant pressure, thus suggesting high risk cold-associated vessel injuries. II maintained (significant decrease SI) response Conclusion. Apparently, moderate does not disturb protective system residents North predomination sympathicotonia. week Northerners be considered developing arterial hypertension.