This study aims to more accurately assess cardiac function, ventilation and exercise capacity in a non-invasive fashion, and to better characterize exercise intolerance in the setting of three populations of individuals with chronic diseases of childhood (acute lymphoblastic leukemia (ALL), chronic lung disease (CLD) of prematurity, and post-heart transplant (HT))

Physical activity in childhood is an integral part of maintaining health and quality of life. Children who participate in routine physical activity are more likely to maintain a healthy body weight and are less likely to have heart disease, type 2 diabetes and high blood pressure as adults. Children with chronic disease are often limited from full participation in exercise for various reasons -perceived physical limitations, either from the patient and family or from their medical provider, or because of symptoms which cause exercise to feel uncomfortable. As the number of children living and aging with chronic disease continues to grow, the researchers are hoping to expand the current exercise testing capabilities for both clinical care and research in order to (i) provide data to permit formulation of evidence-based guidelines for exercise in chronic childhood disease; (ii) improve understanding of limitations to exercise in this growing population; (iii) learn long-term implications of chronic childhood disease as these individuals enter adulthood.

Inclusion Criteria:

• Cases:

  • Acute lymphoblastic leukemia survivor, OR living with chronic lung disease of prematurity, OR living with heart transplant
  • 8-25 years old
  • Height: ≥ 48 inches
  • Ambulatory without assistance
  • English speaking
  • Normotensive (<95th percentile for age; okay if managed with antihypertensive medication)
  • SpO2 >92%
  • Not pregnant
  • ALL survivor specific: must have completed therapy ≥ 3 months prior to study entry

• Controls

  • 8-25 years old
  • Height: ≥ 48 inches
  • Ambulatory without assistance
  • English speaking
  • No history of arrhythmia or known cardiac dysfunction at baseline
  • Normotensive (<95th percentile for age; okay if managed with antihypertensive medication)
  • SpO2 >95%
  • Not pregnant

Exclusion Criteria:

• Cases:

  • ALL specific: received cranial radiation, bone marrow transplant recipients
  • Investigator or patient's primary physician deems the patient unsuitable for the study

• Controls:

  • History of malignancy, CLD or HT or any other diagnosis which may reduce cardiorespiratory function
  • Investigator deems the patient unsuitable for the study

The case participants are the ALL survivors, CLD due to prematurity patients, and post-HT recipients. The control participants can be medical students, UMN staff's children, UMN/Fairview staff, medical residents and undergraduate or graduate students. The remaining controls will be from other UMMCH clinics with conditions unlikely to impact exercise capacity such as dermatology, orthopedics or sports medicine and the University Children's Clinic. Approval will be granted from the treating physician before approaching the control participants