Effect of High Altitude Exposure, Acclimatization and Re-exposure on Right Ventricular Function in Lowlanders

Study Overview
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Brief Summary
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Prospective interventional trial in lowlanders evaluating effect of acute exposure, acclimatization and re-exposure to high altitude

Detailed Description
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Low altitude baseline measurements will be performed in Santiago de Chile, 520 m, over the course of 3 days. Participants will then travel by commercial airline (5 h flight) and by bus (3 h ride) to the ALMA base camp located at 2900 m near San Pedro de Atacama, northern Chile. Participants will stay there for the next 7 nights and they will be spend the days (6-8 h daily) at the telescope station at 5050 m while undergoing physiological testing. Daily transports from 2900 to 5050 m will be by car (1 h ride, one way). After the first 7 day altitude sojourn participants will return to the Santiago area (520 m) for a 7 day recovery period. A second altitude sojourn cycle with an identical schedule as the one described above and a final low altitude stay of 3 days will follow. Measurements on study subjects will be performed at baseline (lowland, Santiago de Chile), then at 2nd day of altitude exposure and 7th day at altitude before returning to lowland; those are repeated in the second altitude sojourn cycle. Measurements will be conducted by qualified specialists using a portable ultrasound device.

Official Title
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Effect of High Altitude Exposure, Acclimatization and Re-exposure on Right Ventricular Function in Lowlanders

Conditions
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Effect of High Altitude

Intervention / Treatment
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* Other: Altitude exposure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Born, raised and currently living <800m No overnight stay at altitudes >1500 m 4 weeks before the study Exclusion Criteria: Previous altitude intolerance to altitude <3000 m Pregnancy Health impairment, which requires regular treatment

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Altitude exposure<br>Acute high altitude exposure followed by 7 day acclimatization and reexposure after 7 days at low altitude | Other: Altitude exposure<br>* Altitude exposure<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Systolic pulmonary artery pressure measured by echocardiography | Change in systolic pulmonary artery pressure over the course of high altitude exposure during 2 sojourns at 5050 m | [Time Frame: lowland baseline at 520m, day 2; first sojourn at 5050 m, day 2, 7; second sojourn at 5050 m, day 2, 7] | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Indices of right ventricular dysfunction |  | [Time Frame: lowland baseline at 520m, day 2; first sojourn at 5050 m, day 2, 7; sec |