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Exercise performance after pediatric heart transplantation
D T Hsu1, R P Garofano, J M Douglas
1Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, NY 10032.
Insights
Pediatric heart transplant recipients show reduced exercise capacity, which remains stable post-transplant. Younger age at transplantation was linked to better exercise performance in these children.
Area of Science:
- Pediatric Cardiology
- Transplantation Medicine
- Exercise Physiology
Background:
- Children awaiting heart transplantation experience significant exercise limitations.
- Assessing post-transplant exercise capacity is crucial for pediatric recipients.
Purpose of the Study:
- To evaluate exercise capacity in children following heart transplantation.
- To identify factors influencing exercise performance in this population.
Main Methods:
- Progressive cycle ergometry was used to test 31 pediatric heart transplant recipients.
- Measurements included maximum workload (Wmax), peak oxygen consumption (VO2), and maximum heart rate (HRmax).
- Exercise capacity was categorized as normal (Wmax ≥ 75% predicted) or decreased (Wmax < 75% predicted).
Main Results:
- At initial testing (1.3 years post-transplant), 25 out of 31 patients had decreased exercise capacity.
- Peak VO2 was significantly higher in patients with normal versus decreased exercise capacity.
- Younger age at transplantation correlated with normal exercise capacity.
Conclusions:
- Pediatric heart transplant recipients exhibit decreased, yet stable, exercise capacity.
- Findings are comparable to those observed in adult heart transplant patients.
Background:
Children awaiting heart transplantation have severe limitations in their ability to exercise. The purpose of this study was to assess exercise capacity after pediatric heart transplantation and to identify factors influencing exercise performance.
Methods And Results:
Progressive cycle ergometry testing was performed in 31 patients at 1.3 +/- 0.8 years after transplantation, and in 16 patients, follow-up studies were performed at 3.3 +/- 1.3 years after transplantation. Maximum work load (Wmax), peak oxygen consumption (VO2), and maximum heart rate (HRmax) were measured. Exercise capacity was defined as normal if Wmax was > or = 75% of predicted values and decreased if Wmax was < 75% of predicted values. Differences in age at transplantation, sex, diagnosis, duration of heart failure, New York Heart Association class before transplantation, resting cardiac index, body mass index, and rejections per patient month were compared between patients with normal and decreased exercise capacity. At initial study, Wmax was 62 +/- 38 W or 61% of that predicted, peak VO2 was 20 +/- 6 mL.kg-1 x min-1 (63% of that predicted), and HRmax was 136 +/- 22 beats per minute (66% of that predicted) for all 31 patients. Six patients had normal exercise capacity, and 25 patients had decreased exercise capacity. Peak VO2 was significantly higher in the normal versus the decreased exercise capacity patients (26 +/- 5 vs 19 +/- 5 mg.kg-1 x min-1). The mean age at transplantation was significantly less in patients with normal exercise capacity: 8.2 +/- 4.6 versus 12.5 +/- 3.6 years for patients with decreased capacity. On follow-up study, no significant differences in Wmax, peak VO2, or HRmax were found from the initial test.
Conclusions:
Similar to results obtained in adult patients, exercise capacity was decreased but stable in pediatric patients after heart transplantation.