An interventional study of Descent and re-ascent (2850m, sea level) in High Altitude Effects, High Altitude and Pulmonary Vascular Disease, sponsored by Silvia Ulrich Somaini. Not yet recruiting at 1 site in Switzerland. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-09-03.
Sponsored by Silvia Ulrich Somaini · Not applicable, Interventional, and Supportive care
To study the effect of relocation from high altitude (Quito Ecuador: 2850m) to sea level and re-ascent from sea level to 2850m on heart rate variability and other hemodynamic parameters in patients with pulmonary arterial hypertension PAH, who live permanently >2600m.
The aim of this research is to investigate the heart rate variability and other hemodynamic outcomes during the descent from 2850m to sea level and during re-ascent from sea level to 2850m in patients with diagnosed pulmonary arterial hypertension according to guidelines, who permanently live at high altitude over 2600m
216 studies on the registry are indexed under Altitude Sickness; 46 are open to participants now.
This study's planned enrollment of 20 is below the median of 34 across 178 interventional studies indexed under Altitude Sickness.
Browse Altitude Sickness studies →Silvia Ulrich Somaini is the lead sponsor of 17 studies on the registry; 16 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
FEV1
From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Assessment of heart rate variability and other hemodynamic outcomes in patients with pulmonary arterial disease during descent from 2850m to sea level and during re-ascent from sea level (after one week stay) back near their living altitude at 2850m
Behavioral: Descent and re-ascent (2850m, sea level)
Descent from 2850m to sea level (in one day by bus) and re-ascent after 7 days from sea level to 2850m (in one day by bus)
Heart rate variability HRV during descent and re-ascent
Difference/change in heart rate variability at different altitudes during descent (2850m to sea level) and during re-ascent after 7 days (sea level to 2850m) in patients with pulmonary arterial hypertension
Time frame: From day of descent (day 1) and day of re-ascent (day 8)
SpO2 during descent and re-ascent
Difference/change in SpO2 at different altitudes during descent (2850m to sea level) and during re-ascent after 7 days (sea level to 2850m) in patients with pulmonary arterial hypertension
Time frame: From day of descent (day 1) and day of re-ascent (day 8)
ECG-Repolarization during descent and re-ascent
Difference/change in ECG-repolarization at different altitudes during descent (2850m to sea level) and during re-ascent after 7 days (sea level to 2850m) in patients with pulmonary arterial hypertension
Time frame: From day of descent (day 1) and day of re-ascent (day 8)
Cardial arrhythmias during descent and re-ascent
Occurrence/changes in cardial arrhythmias at different altitudes during descent (2850m to sea level) and during re-ascent after 7 days (sea level to 2850m) in patients with pulmonary arterial hypertension
Time frame: From day of descent (day 1) and day of re-ascent (day 8)
Pulse transit time during descent and re-ascent
Occurrence and difference/change in pulse transit time (drops) at different altitudes during descent (2850m to sea level) and during re-ascent after 7 days (sea level to 2850m) in patients with pulmonary arterial hypertension
Time frame: From day of descent (day 1) and day of re-ascent (day 8)
Plan to share: Yes — Data will be provided upon request and based on a clear intention reviewed by an ethical review board.
No publications or documents are linked to this record.
Start is estimated for Sep 2026; primary completion for Oct 2026, 0 months later.
Of 76 non-industry interventional studies with no phase under Altitude Sickness, half reached primary completion within 9 months of starting (the median), counting those still running; a quarter within 3 and three quarters within 21. This study's planned 0 months is below that.
Counting every sponsor, half of 76 studies reached it within 9 months; a quarter within 3 and three quarters within 21.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Silvia Ulrich Somaini