The study will measure both myocardial dysfunction and inflammation as it is related to the severity of cardiac arrest, and their association with post-cardiac arrest morbidity and mortality. The study will also determine how the change in both myocardial function and inflammatory markers over time is association with outcomes.

iTONE will study the impact of a 4-month home exercise program on physical activity levels, skeletal muscle mass and strength, functional health status, and quality of life in children and teenagers with pulmonary hypertension. Participants will receive home exercise prescriptions from the CHOP exercise trainers, tailored to their interests and abilities. Participants will wear a smartwatch that tracks activity and communicates with a digital health platform connected to the study team.

The purpose of this research study is to learn more about improving the treatment and outcomes for patients who have a diagnosis of a single ventricle, such as Hypoplastic Left Heart Syndrome (HLHS) or similar heart defects. You will be asked to fill out a questionnaire called the Ages and Stages Questionnaire about your child. It is used widely in pediatrics to check on babies development. We will ask you to fill this out about every three months during your childs 15 months of life. Also, information will be collected about your childs surgeries, clinic visits and hospital stays from diagnosis through the first year of life. The information may be used to help us understand an infant's response to surgery and medical treatment and may be used to improve care for children with single ventricles.