Author/Editor     Zupet, Petra
Title     Vpliv hipoksije na variabilnost srčnega ritma
Type     monografija
Place     Ljubljana
Publisher     Medicinska fakulteta
Publication year     2006
Volume     str. 73
Language     slo
Abstract     In recent years, the role of the autonomous nervous system has become very important. The results of the studies carried out in order to establish the influence of hypoxia on the heart rate variability indicate fairly uniformly a fall in the HF component and a reduction in the activity of the parasympathetic nervous system. As regards the changes in the LF component, the results are, however, contradictory. The aim of our research was to study the influence of acute exposure to hypobaric hypoxia on the activity of the autonomous nervous system of the heart in natural conditions and to assess the events during physical activity in these conditions. Nine non-acclimatized healthy males (age 43.7 +- 7.3 years) took part in the study. Before the expedition, the maximal oxygen consumption of the participants was measured by means of the load on the treadmill. Heart rate was determined at 50 and 75% of maximal oxygen consumption. During the week prior to their departure, measurements were carried out at an altitude of 400 metres; this altitude was later used as a reference altitude. At the beginning of each measurement heart rate was recorded using the high-resolution electrocardiograph and the Polar heartbeat measuring device. Then the subjects underwent the step test using the metronome; they were required to step up onto and down from a standard 50-cm high footstool. The speed of stepping was determined individually in the following way: heart rate during stepping corresponded to the previously determined heart rate for a specific level of load. When the oxygen consumption levelled off at a particular level, we began recording heart rhythm. Heart rate between the above-mentioned loads was monitored for 4 minutes using the Polar. Field measurements: The heart rate measurements were also taken and recorded in the same way at an altitude of 3200 metres and at an altitude of 4200 metres. (Abstract truncated at 2000 characters)
Descriptors     ANOXIA
HEART RATE
EXERCISE TEST
OXYGEN CONSUMPTION
ELECTROCARDIOGRAPHY
ADULT
FOURIER ANALYSIS