High Altitude Pulmonary Hypertension, Maximal Exercise Capacity
Conditions
Brief summary
The impact of hypoxia on maximal work rate during incremental ramp exercise within 3-6 hours after arriving at 2500m of high altitude in patients with precapillary pulmonary hypertension
Interventions
PROCEDUREMaximal Exercise Capacity
Maximal Exercise Capacity in incremental ramp exercise tests.
Sponsors
University of Zurich
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
Patients will be exposed to ambient air at 490m vs. hypoxic air at 2500m in a randomized sequence according to a cross-over design
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Informed consent as documented by signature (Appendix Informed Consent Form) * PH class I (PAH) or IV (CTEPH) diagnosed according to guidelines: mean pulmonary artery pressure \>20 mmHg, pulmonary vascular resistance ≥3 wood units, pulmonary arterial wedge pressure ≤15 mmHg during baseline measures at the diagnostic right-heart catheterization
Exclusion criteria
* resting partial pressure of oxygen \<8 kilopascal at Zurich at 490 m low altitude * exposure to an altitude \>1000 m for ≥3 nights during the last 2 weeks before the study * inability to follow the procedures of the study * other clinically significant concomitant end-stage disease (e.g., renal failure, hepatic dysfunction)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Maximal work rate | 30 hours | Change in maximal work rate in Watt at 2500 vs. 490 m |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Heart rate | 30 hours | Change in cardiorespiratory measurements: heart rate during a cycle incremental ramp exercise test at high altitude vs. low altitude |
| Ventilation | 30 hours | Change in cardiorespiratory measurements: ventilation during a cycle incremental ramp exercise test at high altitude vs. low altitude |
| Oxygen uptake | 30 hours | Change in cardiorespiratory measurements: Oxygen uptake, SpO2, blood gases during a cycle incremental ramp exercise test at high altitude vs. low altitude |
| Arterial blood oxygenation saturation | 30 hours | Change in cardiorespiratory measurements: Oxygenation (SpO2) during a cycle incremental ramp exercise test at high altitude vs. low altitude |
| Blood gases | 30 hours | Change in blood gases during a cycle incremental ramp exercise test at high altitude vs. low altitude |
| Hemodynamics | 30 hours | Change in hemodynamics assessed by echocardiography |
| Borg dyspnoea and leg fatigue scale | 30 hours | Change in post-exercise Borg dyspnoea and leg fatigue scale during a cycle incremental ramp exercise test at high altitude vs. low altitude |
| Electro cardiography: Cardiac arrhythmia | 30 hours | Incidence of cardiac arrhythmia during cycle exercise tests at high altitude vs. low altitude |
| Electro cardiography | 30 hours | Prevalence of abnormal resting electro cardiography (ECG) at high altitude vs. low altitude |
| Electro cardiography :ST-segment changes | 30 hours | Difference in ST-segment changes during cycle incremental ramp and constant work-rate exercise tests at high altitude vs. low altitude |
| Electro cardiography: ST-segment changes under oxygen | 30 hours | 7Difference in ST-segment changes during cycle exercise tests without and with oxygen at high altitude |
| Electro cardiography: Clinically relevant ischemia | 30 hour | Incidence of clinically relevant ischemia (\>1mm ST-segment depression) during cycle exercise tests at high altitude vs. low altitude |
| Electro cardiography: QT-Interval | 30 hours | Change of corrected QT-Interval, during cycle exercise tests at high vs. low altitude |
| Electro cardiography: PQ-Interval | 30 hours | Change of corrected PQ-Interval, during cycle exercise tests at high vs. low altitude |
| Rate pressure product | 30 hours | Change of corrected Rate pressure product, during cycle exercise tests at high vs. low altitude |
| Visual Analogue Scale for dyspnea | 30 hours | Change Visual Analogue Scale at high altitude vs. low altitude according to a 10cm scale from left to right, where the subject has to mark dyspnea with higher values in cm meaning worse dyspnea |
Countries
Switzerland
Outcome results
None listed