@article {Udjus2561, author = {Camilla Udjus and Torbj{\o}rn Tunestveit and Pavel Hoffmann and Ivar Sjaastad and Karl-Otto Larsen and Ole Henning Skj{\o}nsberg and Ulla Hj{\o}rnholm and Morten Rostrup}, title = {High altitude affects the heart}, volume = {56}, number = {suppl 64}, elocation-id = {2561}, year = {2020}, doi = {10.1183/13993003.congress-2020.2561}, publisher = {European Respiratory Society}, abstract = {Background: A zest for mountain climbing has developed, and the number of deaths related to this activity has risen. Hypobaric hypoxia, causing hypoxemia and tissue hypoxia, triggers numerous responses in the body such as acute mountain sickness, pulmonary edema and cardiac arrhythmias. Reduction in skeletal muscle mass is also a result of high-altitude climbing, and this prompted us to study whether cardiac muscle mass is altered, as well.Objective: To explore whether myocardial mass and function are altered after exposure to extreme altitude, and to investigate if possible changes are reversible.Methods: Magnetic resonance imaging of the heart and blood samples were obtained from ten mountain climbers before departure (baseline), directly after return and 1 month after expeditions exceeding 8000 meters above sea level.Results: Left ventricular mass was reduced by 11.8{\textpm}10.9 g after high-altitude climbing (p\<0.01). After 1 month, myocardial mass was restored to baseline values. High altitude induced a reduction in left ventricle end diastolic volume (20.8{\textpm}24.2 ml, p\<0.05), restored after 1 month. Ejection fraction was also reduced after high altitude (3.5{\textpm}3.2\%, p\<0.01), and restored after 1 month. Hypoxia resulted in increased levels of haemoglobin (1.3{\textpm}0.9 g/dL, p\<0.001), haematocrit (0.045{\textpm}0.035, p\<0.001) and proBNP (2.7{\textpm}4.4 pmol/L, p\<0.05), whereas creatine kinase (52.5{\textpm}47.8 U/L, p\<0.01) was reduced, also after 1 month.Conclusion: High altitude mountain climbing induced a reduction in left ventricle mass, end diastolic volume and ejection fraction and a rise in proBNP, indicating a catabolic effect on the myocardium and cardiac dysfunction, which proved to be reversible within one month at sea level.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 2561.This abstract was presented at the 2020 ERS International Congress, in session {\textquotedblleft}Respiratory viruses in the "pre COVID-19" era{\textquotedblright}.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/56/suppl_64/2561}, eprint = {https://erj.ersjournals.com/content}, journal = {European Respiratory Journal} }