An observational study in Ventricular Dysfunction, Right and Hypoxia, sponsored by University of Colorado, Denver. Completed at 1 site in United States. Open to participants aged 18 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2023-05-09.
Sponsored by University of Colorado, Denver · Observational
The purpose of this study is to better understand how hypoxia (low oxygen) affects resting and exertional right ventricular function in healthy individuals.
The right ventricle plays a critical role in exercise. As workload increases with exercise, the right ventricle augments contractility and lusitropy (diastolic relaxation) to accommodate increased venous return (preload) and pulmonary arterial pressure (afterload). Using gold-standard pressure-volume analysis, the investigators have shown that impairments in right ventricular function limit functional capacity among individuals with cardiovascular disease, heart failure and pulmonary hypertension. In addition, the investigators have characterized right ventricular function during exercise in the healthy heart using these techniques. Hypoxia increases pulmonary arterial pressure via hypoxic pulmonary vasoconstriction. By increasing right ventricular afterload, hypoxia may compromise exercise capacity. However, data regarding the impact of hypoxia on right ventricular performance are lacking.
This is a human physiology study of resting and exertional right ventricular function under control (normoxic) and hypoxic conditions. The investigators will use pressure-volume analysis in conjunction with Swan-Ganz catheterization and echocardiography to assess right ventricular performance in healthy individuals at rest and during exercise in normoxia and hypoxia. The study protocol consists of three visits.
In Visits 1 and 2, heart rate/rhythm, oxygen saturation, blood pressure, gas exchange parameters (oxygen uptake [VO2], carbon dioxide production [VCO2], and minute ventilation), and rated perceived exertion will be monitored. Cardiopulmonary exercise testing (CPET) will be performed on an upright cycle ergometer with workload starting at 0 Watts and increasing every 2 minutes until volitional exhaustion with maximum workload at 8-12 minutes. The order of Visits 1 and 2 will be randomized to reduce the potential for bias from a learning/ordering effect.
In Visit 3, the same non-invasive measurements will be obtained. Additionally, right heart catheterization with Swan-Ganz catheter and conductance catheter placement will be performed. This will provide gold-standard hemodynamic and pressure-volume loop analysis to measure outcomes of right ventricular contractility, lusitropy (diastolic relaxation), afterload, and ventricular-arterial coupling. First, participants will complete submaximal exercise at FiO2=0.21. Submaximal exercise will include 5 minutes at 50% of baseline maximal oxygen uptake (VO2max achieved during Visit 1). After 20 minutes' rest, hemodynamic measurements will be obtained at rest at FiO2 0.21, 0.17, 0.15 and 0.12 to characterize the impact of progressive hypoxia on resting right ventricular hemodynamics. Participants will then perform submaximal exercise (50% VO2 max from hypoxic baseline at Visit 2) at FiO2 0.12. Thereafter, participants will complete a symptom-limited CPET at FiO2 0.12 with monitoring of invasive hemodynamics.
90 studies on the registry are indexed under Ventricular Dysfunction, Right; 28 are open to participants now.
This study's enrollment of 10 is below the median of 100 across 51 observational studies indexed under Ventricular Dysfunction, Right.
Browse Ventricular Dysfunction, Right studies →University of Colorado, Denver is the lead sponsor of 1,543 studies on the registry; 317 are open to participants now.
Of its 147 completed or terminated interventional studies of FDA-regulated products, 92 (63%) have results posted.
Counted across the registry records on this site, refreshed daily.
10 healthy men and women
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.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
10 healthy individuals will be recruited.
Other: Hypoxia
Individuals will be exposed to varying levels of hypoxia according to the protocol detailed above.
Right ventricular contractility measured by conductance catheter
End-systolic elastance (Ees) in mmHg/mL
Time frame: Up to 1 hour
Right ventricular lusitropy (diastolic function) measured by conductance catheter
Minimum dp/dt in mmHg/sec
Time frame: Up to 1 hour
Right ventricular stroke work measured by conductance catheter
Area of pressure-volume loop
Time frame: Up to 1 hour
Mean pulmonary artery pressure measured by right heart catheterization
In mmHg
Time frame: Up to 1 hour
Cardiac output derived from right heart catheterization
In L/min, calculated by Fick equation
Time frame: Up to 1 hour
Workload
Workloads attained with submaximal and maximal exercise testing
Time frame: Up to 1 hour
Maximal oxygen uptake
VO2max achieved in maximal exercise testing
Time frame: Up to 1 hour
Plasma acylcarnitine 10:0 measured by peripheral venous metabolomics (ultra-high performance liquid chromatography coupled to mass spectrometry)
Relative ion count
Time frame: Up to 1 hour
Red blood cell acylcarnitine 10:0 measured by peripheral venous metabolomics (ultra-high performance liquid chromatography coupled to mass spectrometry)
Relative ion count
Time frame: Up to 1 hour
Plan to share: No
Ran from Apr 2022 to primary completion in Aug 2022, 4 months.
Of 25 observational studies under Ventricular Dysfunction, Right, half reached primary completion within 24 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 26. This study's 4 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in May 2023. You cannot join it, but the record below documents what was studied.
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Ventricular Dysfunction, Right →
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