Upright Versus Supine Exercise Testing in Fontan-palliated Patients

Study Overview
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Brief Summary
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Fontan-palliated patients comprise an interesting group of single-ventricle patients who are dependent upon passive return of blood from the body to the lungs. Systemic venous pressures are therefore quite elevated, and one study demonstrated that venous capacitance was diminished. In addition, these patients have markedly diminished aerobic capacity (Max VO2). Although one recent study demonstrated that Fontan patients can increase their Max VO2 through diligent cardiac rehabilitation, their ultimate results were still well below average. It has previously been described that normal, healthy subjects have decreased exercise performance in a supine vs upright position. However, due to high venous pressures and the need for systemic venous return to overcome gravity in order to perfuse the lungs, one might hypothesize that Fontan patients would have increased exercise performance in a supine vs upright position. The investigators are interested in studying this hypothesis.

Official Title
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Study of Upright Versus Supine Exercise Testing in Fontan-palliated Patients, Compared With Healthy Controls, to Evaluate for Postural Effects on Exercise Parameters

Conditions
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Fontan Palliation

Intervention / Treatment
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* Other: Supine positioning
* Other: Upright positioning


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: S/p Fontan palliation > 2 years prior Age 8 to 30 years Exclusion Criteria: Pacemaker dependence Severe hypoxemia (O2 saturation <80%) Recent atrial flutter or other arrhythmias Protein losing enteropathy (PLE) Severe atrioventricular valve regurgitation History of cardiac arrest Significant comorbidities (renal failure, asthma, etc).

Ages Eligible for Study
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Minimum Age: 8 Years
Maximum Age: 30 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Fontan patients<br>Subjects will undergo exercise testing in both the supine and upright positions | Other: Supine positioning<br>* Subjects underwent exercise testing on a stationary bicycle in the supine position<br>Other: Upright positioning<br>* Subjects underwent exercise testing on a stationary bicycle in the upright position<br>|
| Healthy controls<br>Subjects will undergo exercise testing in both the supine and upright positions | Other: Supine positioning<br>* Subjects underwent exercise testing on a stationary bicycle in the supine position<br>Other: Upright positioning<br>* Subjects underwent exercise testing on a stationary bicycle in the upright position<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Exercise Capacity | Watts | 40 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak Oxygen Volume (Peak VO2) | milliliters per kilogram of body weight per minute (ml/kg/min) | 40 minutes | 
| Peak Heart Rate | beats per minute | 40 minutes | 
| Peak Pulmonary Artery Pressure | millimeters of mercury (mmHg) | 40 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Supine, Upright