Clinical Trials

Inclusion Criteria:

1. Children 13 years of age and older and adults with known or suspected unilateral proximal pulmonary artery stenosis referred to participating institutions for elective cardiac catheterization and who undergo unilateral proximal PA angioplasty (with or without stenting) will be enrolled in the study.

Exclusion Criteria:

1. Children under 13 years of age
2. Patients who are incapable of performing a maximal exercise test with expiratory gas analysis
3. Patients who are unable/unwilling to return for follow up exercise/lung perfusion scan testing
4. Patients who undergo multiple vessel dilations
5. Patients with distal /multiple branch PA stenosis
6. Patients who have other interventions during the catheterization such as a percutaneous pulmonary valve replacement that could significantly confound the results of exercise testing and symptoms post procedure. 
7. Patients with non-cardiac medical conditions that could affect ventilation such as neuromuscular disorders, myopathies, airway obstruction, chronic metabolic acidosis
8. Patients who have not had cardiopulmonary exercise testing and lung perfusion scan/cardiac MRI to assess differential pulmonary blood flow before the catheterization