Effects of a fast cable car ascent to an altitude of 2700 m on EEG and ECG

Abstract

AbstractIntheEasternAlps,theDachsteinmassifwithaheightofalmost3000misanideallocationforinvestigatingtheeffectsofchangesinaltitudeon the human body. Within a few minutes, a cable car facilitates an ascent from 1702 to 2700m above sea level, where the partial pressure ofoxygen is about 550mmHg (as compared to 760mmHg at sea level). In this study, 10 healthy subjects performed a reaction time task at 990mand2700minaltitude.Thesubjectswereinstructedtoperformarighthandindexfingermovementasfastaspossibleafteragreenlightflashed(repeated 50 times). The corresponding electrocardiogram (ECG) and the electroencephalogram (EEG) were recorded. From the ECG heartrateandheartratevariabilitymeasuresinthetimeandfrequencydomainwerecalculated.Anevent-relateddesynchronization/synchronization(ERD/ERS) analysis was performed with the EEG data. Finally, the EEG activity and the ECG parameters were correlated. 13141516171819 The study showed that with the fast ascent to 2700m the heart rate increased and the heart rate variability measures decreased. Thecorrelation analysis indicated a close relationship between the EEG activity and the heart rate and heart rate variability. Furthermore it wasshown for the first time that the beta ERS in the 14–18Hz frequency range (post-movement beta ERS) was significantly reduced at highaltitude. Very interesting also is the loss of correlation between EEG activity and cardiovascular measures during finger movement at highaltitude. The suppressed post-movement beta ERS at the altitude of 2700m may be interpreted as results of an increased cortical excitabilitylevel when compared with the reference altitude at 990m above sea level.