Mechanisms of Dysfunction and the Influence of Exercise on Cardiac and Musculoskeletal Function

Mechanisms of Dysfunction and the Influence of Exercise on Cardiac and Musculoskeletal Function in Children After the Fontan Procedure

Primary Objective: To determine if impairments in cardiac and musculoskeletal function and metabolism exist in Fontan children.

Secondary Objectives:

1. To determine if impairments do exist, are they related to exercise capacity.
2. To determine if a 12-week exercise training intervention improves cardiac and/or musculoskeletal metabolism.

Hypothesis: The investigators hypothesize that abnormalities in cardiac and skeletal function are evident, influence exercise capacity, and can be improved with exercise training.

This proposed research provides an interdisciplinary approach to understanding exercise intolerance by examining cardiac and musculoskeletal metabolism in a unique cohort of children with congenital heart disease. Study findings may more importantly lead to evidence-based exercise interventions that promote improvements in overall physical health, quality of life, and functional status for Fontan children. Furthermore, this pilot study will lead to the development of a novel research protocol which may be applied to larger Fontan and other congenital heart disease cohorts. This study will also provide preliminary data to develop and conduct a larger clinical research project.

Inclusion Criteria:

Fontan Patients:

1. Patients who have had the Fontan cardiac procedure
2. 10-16 years of age
3. Written Informed Consent

Healthy Controls:

1. 10 - 16 years of age
2. Written Informed Consent

Exclusion Criteria:

Fontan Patients:

1. Contraindication to exercise
2. Physically active (i.e., ≥ 60 minute of moderate-vigorous activity) (Strong et al., 2005)
3. Patients in whom MRI is contraindicated (e.g. pacemaker, ocular metal, claustrophobia, tattoos)
4. Patients with a known allergy to gadolinium.
5. Patients with a history of allergic disposition or have anaphylactic reactions
6. Moderate-to-severe renal impairment (defined as having a GFR/ eGFR < 60 mL/min)
7. Have Sickle Cell anemia
8. Known pregnancy, or breast feeding
9. Patient is uncooperative during a MRI without sedation or anesthesia

Healthy Controls:

1. Contraindication to exercise
2. Physically active (i.e., ≥ 60 minute of moderate-vigorous activity) (Strong et al., 2005)
3. Patients in whom MRI is contraindicated (e.g. pacemaker, ocular metal, claustrophobia, tattoos, pregnancy)
4. Patient is uncooperative during a MRI without sedation or anesthesia