While it is commonly known that heart function is reduced at high altitude, a team from Cardiff Metropolitan University, the University of British Columbia, and Loma Linda University School of Medicine, is a step closer to explaining why this is.

New research published in The Journal of Physiology indicates why high altitude reduces the amount of blood the heart pumps around the body with each beat; which is useful to people who live, travel and exercise at high altitudes.

As the body acclimatises to high altitudes (over 3000m), the reduction in oxygen availability leads to a lower volume of blood circulating around the body and an increase in the pressure in the blood vessels of the lungs. The researchers found that both factors contribute to a reduction in the volume of blood the heart can eject with each beat, but importantly neither affect the ability to perform maximal physical work.

Cardiff Met reports the research involved collecting data on how the heart and pulmonary blood vessels adapt to life with less oxygen. A team of lowland natives of European descent spent two weeks at the Barcroft Laboratory on White Mountain, a remote research facility in California sitting 3800m above sea level.

Michael Stembridge, a Lecturer in Sport and Exercise Physiology at Cardiff Met, and chief investigator on the project, said “Our research team are committed to finding the answers to how the human body adapts, survives and thrives at high altitude. This includes looking at how lowlanders adapt when we travel, but also populations who have been residing in Earth’s mountainous regions for thousands of years.”

Currently a number of the research team are packing ready to depart for an expedition that will focus on high altitude natives who live and work in the industrial mines of the Cerro de Pasco region of the Andean mountains.

Michael Stembridge said “Unfortunately, up to a third of these individuals experience long-term ill health due to their residence at high altitude, a condition termed ‘Chronic Mountain Sickness’. The purpose of the expedition is to better understand the underlying physiology of the condition and explore potential therapeutic targets and ways to improve it.”