Effect of altitude on cardiovascular responses to voluntary apnea in Nepali Sherpa

Our lab has demonstrated that voluntary apneas (i.e., breath-holds) at high altitude cause decreases in heart rate in lowlander populations. Apneas at altitude also cause cardiac arrhythmias in a majority of lowlanders. Unlike lowlanders, native highlanders (e.g., Nepali Sherpa) do not get the same decreased heart rate and cardiac arrhythmias during voluntary apneas at high altitude. However, a recent study showed that mountaineers climbing Mount Everest—almost all of which were Sherpa—got many cardiac arrhythmias over a multi-day ascent. Like apnea, exercise is an autonomic nervous system stressor, and these data therefore contradict our findings. I will therefore re-assess the cardiac responses to apneas in Sherpa at low and graded high altitude to uncover the progressive effect of altitude on the heart’s response to nervous system stress. Uncovering the physiological mechanisms described above provides new insights into the adaptations of the Sherpa to altitude. This project furthers Dr. Steinback’s research into physiological mechanisms during apneas. This project also furthers Dr. Mahotra’s clinical understanding via the population-specific outcomes not available through research in lowlanders. We hope the physiology we uncover informs future clinical research with meaningful impacts on the health of Nepali Sherpa.

Faculty Supervisor:

Craig Steinback

Student:

Partner:

Tribhuvan University

Discipline:

Life Sciences

Sector:

Life Sciences (not health); Environmental Science and Technology

University:

University of Alberta

Program: