The baseline characteristics of 4 participants and the medication history in this climb.

<p>The baseline characteristics of 4 participants and the medication history in this climb.</p

The screenshot of the ECG software interface at the hospital side.

<p>The upper right corner shows the elevation. The lower right corner shows his location on Google Earth. Top: At camp 4 (7854 m) the heart rate of the 34 year-old climber was 102 bpm. Bottom: At camp 3 (7164 m) the heart rate of the 34 year-old climber is 98 bpm.</p

Illustration of the real-time ECG satellite transmission system.

<p>Left to Right: One lead ECG is transmitted via Bluetooth to a PDA, which forwards the signal to a satellite phone again through Bluetooth. The satellite phone acts as a modem and sends the data through a satellite to the servers in Taiwan, which then dispatches the ECG data to the smart phone and the PC of the team doctor.</p

The lowest resting heart rate of participants at each camp in Mount Everest.

<p>Withdraw: The particular participant didn’t reach this camp.</p><p>NM: The heart rate is not measured.</p>#<p>Maximum age-related heart rate (MAHR) is calculated by maximal age minus related heart rate, and the unit is beat per minute (bpm).</p>¶<p>The environment characteristics for each camp, including the altitude (meter; m), fraction of inspired oxygen (FiO₂), and the amount of mandatory oxygen supply, are shown.</p><p>The lowest resting heart rates of participants at each camp were presented as the value (%; the percentage compared to MAHR).</p

The differences between the measured heart rate (HR) published in the respective references and predicted heart rate (HR) calculated by method used in this study.

<p>HR = heart rate; m = meter;</p>a<p>The data were cited from the Reference #19. Predict HR at camp 2 = measured HR at base camp × 6300 m/5400 m; % of difference = percentage of the difference between measured HR and predict HR.</p>b<p>The data were cited from the Reference #22. Predict HR at camp 4 = measured HR at camp 2 × 8000 m/6550 m.</p>#<p>The heart rates under various conditions were measured, including without O₂ supplement (regular air), 1L O₂ supplement, or 2L O₂ supplement.</p