Children's exercise capability after orthotopic heart transplant

The aim of this research was to study the exercise capability of heart transplanted (HT) children in order to provide a description of their physical fitness status that could be used to define protocols of rehabilitation based on supervised exercise programs. Eleven HT children in stable clinical conditions (6 males and 5 females) and 9 control subjects (4 males and 5 females) were submitted to a maximal exercise stress test on a treadmill following the Bruce protocol. At rest, during test execution and recovery, heart rate, oxyen intake, and pulmonary ventilation were continuously measured. Exercise duration was significantly shorter in HT compared with controls. Rest heart rate was higher in HT than in normal subjects and lower at the end of exercise. Heart rate slowly increased during exercise and the recovery phase was slower than in controls. Peak oxygen intake was reduced in HT both absolutely and relatively to body mass. All HT subjects showed an increase in pulmonary ventilation which was not proportionate to the matabolic demand. These results do not provide any evidence of a real clinical contraindication to the practice of controlled doses of physical exercise in HT subjects. On the contrary, as already documented in adults, this should promote a faster and better recovery of normal physical capability in HT children.