Fontan Circulation
Conditions
Keywords
Skeletal muscle, Fontan patients, Congenital heart disease, muscle function
Brief summary
Groundbreaking cardiac surgery has significantly improved survival rates for patients with single-chamber hearts. However, despite these life-saving interventions, the long-term prognosis remains concerning, with an increased risk of heart failure, sudden cardiac death, and reduced quality of life. The absence of a chamber that pumps blood to the lungs means individuals must rely on their leg muscles to passively return blood and oxygenate the lungs. Unfortunately, studies indicate reduced muscle mass and function in these patients. The aim is to clarify the complex interplay between single-chamber circulation and muscle function, paving the way for targeted interventions such as muscle strengthening training for this unique patient group. Our hypothesis is that muscle mass and function correlate with circulatory limitations, and that muscle strengthening training could, over time, improve both muscle and circulatory function simultaneously. The first part of the project includes tests for maximal oxygen uptake, heart and circulatory function, muscle strength, muscle mass/body composition, and quality of life in adult patients (aged 16 and over) with single-chamber hearts. The study may ultimately lead to improved interventions and exercise recommendations that promote an active lifestyle and enhance health, circulation, and physical function in patients with single-chamber hearts.
Interventions
None listed
Sponsors
Karolinska Institutet
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
16 Years to 50 Years
Healthy volunteers
No
Inclusion criteria
* Diagnosis of a Fontan circulation: individuals who have undergone the Fontan procedure with only one functioning systemic ventricle, confirmed by medical records or attending physician. * Stable clinical status: patients should be clinically stable without significant cardiovascular or renal dysfunction as determined by clinical examinations. * Age range: 16-50 years. * Ability to exercise: Participants must be physically able to participate in the exercise protocol according to a preliminary medical examination. Controls: Age and sex-matched. Healthy (no chronic diseases, assessed by health questionnaire and interview).
Exclusion criteria
* Recent surgery or hospitalization: individuals who have undergone cardiovascular surgery or hospitalization within six months prior to inclusion. * Severe functional limitations: Patients with clear functional limitations unrelated to Fontan physiology, such as musculoskeletal disorders. * Significant comorbidities: Serious non-cardiac comorbidities that may independently affect work capacity, such as advanced pulmonary disease. * Contraindications for exercise testing: Conditions that contraindicate physical testing, such as uncontrolled cardiac arrhythmias or severe heart failure (New York Heart Association III-IV).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Relationship between anterior thigh muscle volume and peak maximal oxygen uptake in patients vs. controls | Baseline visit (single time-point) | Muscle volume is measured in litres using magnetic resonance imaging. VO2peak is measured in L/min and ml/kg/min using cardiopulmonary exercise testing with breath-by-breath gas analyzers. |
| Relationship between knee extension muscle strength and peak maximal oxygen uptake in patients vs. controls | Baseline visit (single time-point) | Muscle strength (isometric peak torque) is measured in Nm using Biodex. VO2peak is measured in L/min and ml/kg/min using cardiopulmonary exercise testing with breath-by-breath gas analyzers. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Anterior thigh muscle fat infiltration in patients vs. controls | Baseline visit (single time-point). | Measured in % using magnetic resonance imaging. |
| Whole body muscle composition in patients vs. controls | Baseline visit (single time-point) | Measured in L and/or per kg body mass using magnetic resonance imaging |
| Quality of life in patients vs. controls and its relationship to muscle function | Baseline visit (single time-point visit) | Quality of life aspects are measured using surveys (SF-36). |
| Cardiac function in patients vs. controls | Baseline visit (single time-point) | Ventricular end-diastolic volume, Ventricular end-systolic volume, and Stroke volume measured in ml/m² |
| Whole body fat composition in patients vs. controls | Baseline visit (single time-point) | Measured in L and/or per kg body mass using magnetic resonance imaging |
Countries
Sweden
Outcome results
None listed