The SUMMIT study was an investigator-initiated, prospective cohort study of healthy volunteers determined to climb Mount Everest.
The research study was performed by the University of Bern in Switzerland and the National Academy of Medical Sciences in Nepal, and champions inclusive and equitable scientific collaboration between Swiss and Nepali scientists. The study was funded by a dedicated grant from the Swiss Polar Institute.
The study has been approved by the Nepal Health Research Council and is registered with www.clinicaltrials.gov (ClinicalTrials.gov Identifier: NCT05676398).
Exposure to high altitudes has been associated with an increased risk of heart rhythm abormalities in healthy subjects. Several physiological adjustments to high altitude account for a potentially pro-arrhythmic milieu. A fall in atmospheric pressure at high altitude decreases the partial pressure of oxygen and causes arterial hypoxemia. At the same time, respiratory alkalosis secondary to hyperventilation causes hypokalemia and hypocalcemia. Both factors facilitate the occurrence of rhythm disturbances, and may be further exacerbated in an adrenergic state with increased epinephrin levels.
In the SUMMIT study, we aimed to assess the incidence of heart rhythm abnormalities at extreme altitude and to evaluate factors associated with their occurrence.
We recorded the heart rhythm of healthy participants during their ascent from basecamp to the summit of Mount Everest by means of a patch attached to the left side of the chest. All participants acted as their controls. Therefore, the heart rhythm was also recorded in the subject’s home environment prior to the climb. Heart rhythm was recorded using the AT-Patch ATP-C130 (ATSens, Korea). The patch is a quarter the size of a one-dollar bill and weighs 13g. It is attached to the left side of the chest. The ATP-C130 has CE mark (Europe) and has been approved as a medical device by the FDA (USA).