Remote real-time ambulatory ECG monitoring of the longest RR interval and corresponding arrhythmias during altitude ascent.

OBJECTIVE

The aim of this study is to characterize the longest RR intervals and associated arrhythmias during the early phase of rapid ascent to high altitude environments using ambulatory electrocardiography (AECG), with the aim of informing strategies to prevent acute high-altitude illness and cardiovascular adverse events.

METHODS

Participants residing at low altitude underwent rapid ascent to high-altitude locations at 3060 m, 3460 m, and 4014 m. Beginning on the first day at altitude, AECG monitoring was conducted for more than 24 h using a Model 401 wearable ECG monitor, enabling remote, real-time data transmission via a 4G network and immediate clinical response to high-risk arrhythmias. Cloud-based storage and analytic platforms facilitated statistical evaluation of the longest RR intervals and corresponding rhythm types.

RESULTS

(1) The longest RR intervals and associated arrhythmias were primarily observed during nighttime sleep. (2) Statistically significant differences (p < 0.05) were found among the three altitude groups in the incidence of the longest RR intervals <1.00 s, abnormal rhythms associated with the longest RR intervals, premature beats corresponding to the longest RR intervals, and sinus pause episodes. (3) The primary arrhythmias associated with the longest RR intervals included ventricular premature beats, second-degree type II atrioventricular block, high-degree atrioventricular block, sinus pause, and atrial fibrillation.

CONCLUSION

Clinically significant bradyarrhythmia may occur during rapid ascent to altitudes between 3060 m and 4014 m, particularly during nocturnal hours. These findings highlight the need to consider targeted preventive attention during nighttime exposure, given the high prevalence of nocturnal bradyarrhythmias. Remote real-time AECG monitoring may serve as a useful tool for early detection and intervention in populations at risk of altitude-related cardiac rhythm disturbances.