|High altitude medicine research on real mountains and under simulated conditions.|
The ARGE Alpinmedizin was founded 2004 at the Karl-Franzens University in Graz. It is an inter-disciplinary co-operation of scientists interested in high-altitude and tourism medicine.
Activities of the organization are:
- co-ordination and support of research projects dealing with high-altitude and tourism medicine
- publication of scientific articles
- organization of scientific meetings, conferences and talks
- co-operation with other high-altitude societies
We are pleased to present one of the projects we accomplished together:
Effects of a fast cable car ascent to an altitude of 2700 meters on EEG and ECG
The Dachstein massif is in the Eastern Alps. It reaches a height of almost 3000m, and is an ideal location for investigating the effects of changes in altitude on the human body. A cable car allows people to ascend to 2700 m within a few minutes, where the partial pressure of oxygen is about 550 mm of mercury compared to 760 mm at sea level.
Ten healthy subjects performed a reaction time task at 990 m and 2700 m altitude. The subjects were instructed to perform a right hand index finger movement as fast as possible after a green light flash. The green light flashed 50 times. The electrocardiogram (ECG) and the electroencephalogram (EEG) were recorded. The ECG analysis showed that the heart rate increased from about 69 to 80 bpm and that the heart rate variability parameters decreased: RMSSD decreased from 33.0 to 14.8 ms, pNN50 from 9.6 to 0.9 %. The spectral analysis of the ECG showed an increase of the normalized LF component from 51.1 to 65.4, a decrease of the normalized HF component from 35.1 to 25.0 and an increase of the LF/HF ratio from 2.1 to 4.4. The event-related desynchronization (ERD) analysis of the EEG data showed that changes in alpha ERD values are not significant, but event-related synchronization (ERS) values in the beta band decrease significantly from around 50 % to 10 %.
The study showed that with the fast ascent to 2700 m, the sympathetic nervous system is getting more dominant compared to the parasympathetic system and that the beta ERS in the 14 to 18 Hz frequency range is significantly reduced. The suppressed post-movement beta ERS at the altitude of 2700 m may therefore be interpreted as a result of an increased cortical excitability level when compared with the reference altitude at 990 m above sea level.
For further information please visit http://www.argealpinmed.at/