Electrocardiogram at an Altitude of 3600 m with Reference to T Wave Depression

The drop in atmospheric pressure at high altitudes results in hypoxemia, a decrease in arterial oxygen saturation (SₐO₂). Changes in sympathetic nerve activity caused by acute hypoxia increases ventilation and heart rate and lowers arterial carbon dioxide, exerting significant demands on the cardiovascular system. Prior studies with exposure to altitudes of up to 7000 meters (22,966 feet) showed decreased voltage of the T wave on the electrocardiogram (ECG) secondary to hypoxia. This study investigates changes in the ECG at an altitude of up to 3600 meters (12,000 feet), the maximum altitude at which pilots can fly without using supplemental oxygen, and a common altitude for recreational trekkers. Physiological and ECG data were collected from 13 subjects who were taken from sea level to 3000 meters or 3600 meters of simulated altitude in a pressure chamber. The results confirmed the authors' hypothesis that a decrease in T wave amplitude would occur, but in fewer subjects than reported in the studies at higher altitudes, and that the effect is likely not due to changes in ventilation, heart rate, SₐO₂ or end-tidal CO₂.

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  • English

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  • Accession Number: 01529260
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 5 2014 4:35PM