Last year in Summit County, 23 people died of heart complications, 19 of which were visitors ascending to higher altitude. Most of these visitors were in their 50s or older and died within one to two days after coming to elevation (Queen, 2017).
Acute exposure to high altitude over 2500 m can cause great strain on the body and is associated with significant alterations to the cardiovascular system such as tissue hypoxia and increased pulmonary artery pressures. Although the concentration of oxygen at elevation is the same at sea level, the air is thinner causing less oxygen to breath. At sea level the percent of effective oxygen concentration is around 20% where as in Summit County the percentage of effective oxygen drops down to 14%. At higher elevation such as the ski areas the percentage of effective oxygen drops down to 13% (Queen, 2017). As a result, the heart will pump faster to increase the delivery of oxygen to the body. The cardiac stress at rest is minimal, however it can be significant during exercise. Anyone with some degree of heart complication can worsen the stress on their heart when coming to higher elevation (Bach, 2013).
Hypoxemia due to high altitude can cause poor oxygenation of the lungs and constriction of blood vessels, causing an increase in pulmonary pressure and increasing hypertension. Therefore, an acute exposure to high altitude can cause cardiovascular stress. Residents of high elevation tend to do better because they have anatomical and physiological changes in their cardiovascular system that allows them to adapt to high-altitude chronic hypoxia (Hurtado et al., 2012).
It is recommended that any patients with cardiovascular disease who are from sea level and planning to come to elevation should slowly acclimatized themselves by staying in Denver for a day or two prior to going above 2500 m. Patients who have stable heart complications should limit their physical activity for the first few days after ascending to elevation.
Hong Nguyen, PA-S
Physician Assistant Student
Red Rocks Community College
Bach, D. (n.d.). Altitude and the Heart: Is Going High Safe for Your Cardiac Patient? Retrieved March 28, 2017, from http://www.expeditionmedicine.co.uk/index.php/advice/resource/r-0034.html
Hurtado, A., Escudero, E., Pando, J., Sharma, S., & Johnson, R. J. (2012). Cardiovascular and renal effects of chronic exposure to high altitude. Nephrology Dialysis Transplantation, 27(Suppl 4), Iv11-Iv16. doi:10.1093/ndt/gfs427
J. Q. (n.d.). High elevation may be linked to visitor heart attach deaths. Summit Daily, pp. 1-4.