Mobile Health Intervention to Improve Exercise in Pediatric PH

This study is testing a mobile health app and wearable device program to help teenagers with pulmonary arterial hypertension (PAH) — a condition where blood pressure in the lungs is dangerously high — stay more physically active. Regular exercise is beneficial for PAH patients, but many avoid it out of fear. The study hopes to show that a safe, guided mobile program can improve exercise habits. **You may be eligible if...** - You are an adolescent between 13 and 19 years old - You have been diagnosed with PAH (idiopathic, heritable, or related to connective tissue disease, drugs, toxins, or simple congenital heart disease like atrial septal defect) - Your PAH is classified as WHO functional class I–III (not the most severe) - Your PAH medication has been stable for at least 3 months - Your lung function and breathing tests are within an acceptable range **You may NOT be eligible if...** - You are confined to a wheelchair or bed - You are currently on an urgent transplant waitlist - You have other conditions that make physical activity unsafe - Your PAH medication has recently changed significantly Talk to your doctor to see if this trial is right for you.