The aim of this 16-week group aerobic training program, delivered remotely via video-conferencing, is to assess program feasibility, and determine if program increases physical activity in adolescents after heart transplant.

Orthotopic heart transplant (OHT) is the definitive therapy for children with cardiac disease, however, survival after transplant is limited, and quality of life after transplant is less than healthy peers'. The transplanted heart usually works well, pumping blood as well as most healthy hearts. As such, the American Heart Association recommends no specific exercise related restrictions for heart transplant recipients. Although most children have normal cardiac function after OHT, children with transplanted hearts have impaired exercise performance, and do not exercise as much as their peers. This finding is concerning, as impaired exercise tolerance is associated with reduced survival, diminished health related quality of life, and depression and anxiety. These factors negatively impact adherence, and further limit graft survival. Thus, identifying interventions that positively impact physical activity and promote graft longevity, like individualized exercise programs, should be a priority for post-transplant care.

Investigators propose that increasing physical activity in children and adolescents after OHT may be a critical modifiable method for increasing graft longevity and improving quality of life. Investigators will explore this through a pilot program. Participants will wear an activity monitor to record physical activity, parents/caregivers and participants will complete surveys, and participants will engage with psychologists and exercise physiologists.

Inclusion Criteria for Patients

• Age 12-18 years old
• More than 12 months removed from their initial heart transplant
• Agreement to participate in study protocol and willing/able to return for follow-up.
• Access to computer and/or internet for uploading health data from wearable electronic activity monitor.
• Access to an electronic device (phone, tablet, or computer) with a camera feature, microphone, and the capacity to use Zoom, the virtual platform which will stream the group exercise session.
• Clinical EKG with normal sinus rhythm
• English language proficiency

Exclusion Criteria for Patients

• Patients who are restricted from exercise
• Patients who are pregnant
• History of pharmaceutically treated rejection within the prior 6 months
• Physical or behavioral conditions that would prevent them from participating in aerobic exercise (i.e., significant motor disability, illness precluding participation in the exercise regimen as described).
• Inability to complete a standard maximal exercise stress test (as defined by those who did not achieve an respiratory exchange ratio (RER)>1.1 and who gave submaximal effort according to exercise physiologist performing EST)
• EKG or ambulatory rhythm monitor performed within the last 12 months which shows 2nd or 3rd degree atrioventricular (AV) block
• Patients with a medication change after their baseline EST expected to affect their heart rate response to exercise (i.e. initiation/discontinuation of a beta-blocker, beta-agonist during exercise, or ivabradine)
• Pacemaker

Inclusion Criteria for Parents

• Parent of a patient that fits all inclusionary/exclusionary eligibility criteria
• English language proficiency at least at a 5th grade level or for limited English proficient (LEP) parents, preferred language proficiency of at least a 5th grade level

Exclusion Criteria for Parents

- Unwilling to complete questionnaires