Exercise stress echocardiography (ESE) may help identify individuals at risk of developing acute mountain sickness (AMS) within hours of arriving at high altitude, according to a study. Researchers found that specific changes in right ventricular function and pulmonary circulation during exercise accurately distinguished participants who went on to develop AMS from those who remained symptom-free.
AMS commonly affects travellers ascending to elevations above 2,500 m and can cause headache, nausea, dizziness, fatigue, and sleep disturbances. Although several risk factors have been identified, clinicians currently have limited tools to predict who will develop the condition before symptoms appear.
Cardiovascular Responses Assessed at High Altitude
The prospective study enrolled 50 healthy adults living at low altitude who completed a staged ascent by bus to 3,600 m.
Within six hours of arrival, participants underwent exercise stress echocardiography to assess right ventricular function and pulmonary haemodynamics before being evaluated for AMS the following morning using the Lake Louise Score.
Twenty-three participants (46%) developed acute mountain sickness, while 27 remained free of symptoms.
Pulmonary Pressure Increased in Participants Who Developed AMS
At peak exercise, participants who later developed AMS demonstrated significantly higher systolic pulmonary artery pressure (SPAP) and pulmonary vascular resistance (PVR) than those who did not.
The AMS group also experienced greater increases in both SPAP and PVR from resting levels during exercise, suggesting a more pronounced pulmonary vascular response to high altitude.
In contrast, markers of right ventricular contractile reserve—including tricuspid annular peak systolic velocity (TV s′) and right ventricular fractional area change (FAC)—showed smaller improvements during exercise, indicating reduced right ventricular functional reserve.
Researchers also observed larger inferior vena cava (IVC) diameters in the AMS group at both rest and peak exercise.
Prediction Model Showed High Accuracy
Using the physiological measurements collected during exercise testing, the investigators developed a prediction model incorporating peak IVC diameter, changes in pulmonary vascular resistance (ΔPVR), and changes in TV s′.
The model achieved an area under the receiver operating characteristic curve (AUC) of 0.865 and correctly classified participants with an overall accuracy of 84%.
These findings suggest that combining measures of pulmonary vascular response and right ventricular function could provide a practical method for identifying individuals at increased risk of developing AMS shortly after arriving at high altitude.
Potential Tool for Early Risk Stratification
The authors conclude that exercise stress echocardiography can detect early cardiovascular adaptations associated with acute mountain sickness before clinical symptoms become apparent.
By identifying abnormal pulmonary vascular and right ventricular responses soon after ascent, the technique could help clinicians recognise individuals at higher risk and guide preventive strategies, monitoring, or decisions regarding further ascent.
The researchers note that larger studies are needed to validate the predictive model and determine how exercise stress echocardiography could be incorporated into routine assessment of travellers, athletes, and workers operating at high altitude.
Reference
Xu Y et al. High-altitude exercise stress echocardiography identifies individuals at risk for acute mountain sickness. BMC Pulm Med. 2026:DOI: 10.1186/s12890-026-04513-7.
