Effect of Acute Hypoxia on RIght VEntRicular Function in Healthy Adults.
RIVER-H
1 other identifier
interventional
18
1 country
2
Brief Summary
More and more people are engaging in sports in the mountains, including individuals with heart or lung diseases. At the same time, such diseases are becoming more common in Switzerland. At high altitude, less oxygen is available, which places stress on the body-particularly on the heart, which has to pump blood through the lungs. How the healthy heart, especially the right ventricle, responds to this stress is still not well understood. Therefore, this study investigates how the heart responds to simulated altitudes of 2,500 m and 4,000 m, both at rest and during light physical activity. The present investigation focuses on healthy individuals in order to establish a reference for future comparisons with patients suffering from cardiopulmonary diseases. The primary objective is to assess how right ventricular function changes under conditions of reduced oxygen availability. In addition, vital signs, changes in blood gases, oxygen levels in blood and tissue and shortness of breath are assessed. The "altitude" is simulated using a special gas mixture that participants inhale. Healthy participants undergo three altitude conditions (490, 2,500, and 4,000 m above sea level). The order of the altitude conditions is assigned at random. The aim is to better understand how the right ventricle and other parameters respond to low-oxygen conditions and how affected patients can be better supported in the future.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at below P25 for not_applicable
Started Mar 2026
Longer than P75 for not_applicable
2 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
February 9, 2026
CompletedFirst Posted
Study publicly available on registry
February 24, 2026
CompletedStudy Start
First participant enrolled
March 11, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
January 1, 2030
ExpectedStudy Completion
Last participant's last visit for all outcomes
January 1, 2030
March 17, 2026
March 1, 2026
3.8 years
February 9, 2026
March 13, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Right ventricular free wall strain
The primary endpoint is defined as the right ventricular free wall strain (RVFWS) from condition normobaric normoxia to condition 4000m for group 1 and from normobaric normoxia to condition 2500m for group 2 at rest. RVFWS will be measured by speckle tracking strain analysis according to the guidelines of the European Association of Cardiology. Speckle tracking echocardiography allows to assess the right ventricular volume and true global RV function without relying on geometric assumption and is a valuable clinical bedside tool for assessing myocardial strain. Tomtec software (Philipps) will be used.
It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.
Secondary Outcomes (19)
Tricuspid annular plane systolic excursion (TAPSE)
It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.
Right ventricular-arterial coupling
It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.
RV/PA
It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.
Stroke volume
It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.
Heart rate
It will be assessed at baseline and continuously measured during each condition (1 hour resting period and during the 10 minutes cycling).
- +14 more secondary outcomes
Study Arms (6)
Arm ABC
OTHERThe participant receives first normobaric normoxia (A), then normobaric hypoxia equal to 2500 m.a.s.l. (B) then normobaric hypoxia representing 4000 m.a.s.l. (C). Condition A represents the control.
Arm ACB
OTHERThe participant receives first normobaric normoxia (A), then normobaric hypoxia representing 4000 m.a.s.l. (C), then normobaric hypoxia equal to 2500 m.a.s.l. (B). Condition A represents the control.
Arm BAC
OTHERThe participant receives first normobaric hypoxia equal to 2500 m.a.s.l. (B), then normobaric normoxia (A), then normobaric hypoxia representing 4000 m.a.s.l. (C). Condition A represents the control.
Arm BCA
OTHERThe participant receives first normobaric hypoxia equal to 2500 m.a.s.l. (B), then normobaric hypoxia representing 4000 m.a.s.l. (C), then normobaric normoxia (A). Condition A represents the control.
Arm CAB
OTHERThe participant receives first normobaric hypoxia representing 4000 m.a.s.l. (C), then normobaric normoxia (A), then normobaric hypoxia equal to 2500 m.a.s.l. (B). Condition A represents the control.
Arm CBA
OTHERThe participant receives first normobaric hypoxia representing 4000 m.a.s.l. (C), then normobaric hypoxia equal to 2500 m.a.s.l. (B), then normobaric normoxia (A). Condition A represents the control.
Interventions
Normobaric hypoxia according to 408m (control/normobaric normoxia), 2500 m and 4000 m above sea-level at rest for 1 hour and at low intensity cycling for 10 minutes (5 min 30 W, 5 min 60 W).
Eligibility Criteria
You may qualify if:
- Signed informed consent
- years (age group young: 18-39.99 years / age group older: 40-80 years)
- All sex and genders -Living \<800m and without altitude exposure \> 2500 m and \> 24h within the last three weeks
You may not qualify if:
- \<18, \>80 years old -Any diagnosed cardiopulmonary condition including past HAPE
- Other clinically significant severe concomitant disease states (e.g. renal, hepatic dysfunction, etc.)
- Inability to follow the procedures of the study due to language problems, psychological neurological disorders or orthopaedic disorders
- Participants permanently living \>800m and altitude exposure \> 2500 m and \>24h within the last three weeks
- Pregnancy: Participants will be asked if pregnant or not, no screening for undetected pregnancy
- Lactating women -Participation in other study with active treatment
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Mona Lichtblaulead
Study Sites (2)
Consultant Clinic of Pulmonology, University Hospital of Zurich
Zurich, Canton of Zurich, 8091, Switzerland
Consultant Clinic of Pulmonology, University Hospital of Zurich
Zurich, 8091, Switzerland
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Mona Lichtblau
University of Zurich
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- TRIPLE
- Who Masked
- PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
- Purpose
- DIAGNOSTIC
- Intervention Model
- CROSSOVER
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR INVESTIGATOR
- PI Title
- PD Dr. med.
Study Record Dates
First Submitted
February 9, 2026
First Posted
February 24, 2026
Study Start
March 11, 2026
Primary Completion (Estimated)
January 1, 2030
Study Completion (Estimated)
January 1, 2030
Last Updated
March 17, 2026
Record last verified: 2026-03