Effects of home-based training at dyspnea threshold in children surgically repaired for congenital heart disease

Abstract

The present investigation was aimed at assessing the effect of home-based training on cardiorespiratory responses in children surgically corrected for congenital heart impairment using dyspnea threshold (DT) as training intensity. A group of 23 children aged 15 +/- 1.4 years who had undergone surgical correction for congenital heart disease (CHD group) and 12 healthy children used as a control group performed an exercise protocol during which aerobic capacity, ventilatory threshold (VT), and DT were assessed. Afterwards, the CHD group was divided into two subgroups: trained and untrained subjects. Training sessions over a period of 2 months were performed at an intensity corresponding to DT by the CHD trained group. Dyspnea was scored according to a visual analog scale during the warm up, at each exercise stage, and during the recovery period. DT was located on the oxygen uptake/dyspnea curve when a sudden increase in the dyspnea score occured, while VT was defined according to the methodology previously employed by Beaver and colleagues. The results showed that children who had undergone surgery for CHD had reduced aerobic capacity. No significant difference was observed between VT and DT in children corrected for CHD. These two thresholds were highly related. Home-based training at DT did not strongly improve aerobic capacity nor did it influence the relationship between VT and DT. Further studies should be conducted to confirm these preliminary findings, particularly when aerobic capacity is improved by training.