Alternations of Heart Rate Variability at Lower Altitude in the Predication of Trekkers With Acute Mountain Sickness at High Altitude

The HRV measurements in total variances, HF, and HF% in trekkers with AMS were statistically significantly lower at high altitude. HF% < 20% (nu) or LF:HF ratio > 1.3 at lower altitudes could be an important predication parameter of trekkers with AMS at higher altitudes.