Effects of exercise training on aerobic fitness in children after open heart surgery.

Graded treadmill tests to maximal exercise were given to 24 children 1 year or more after open-heart surgery and to 26 age- and sex-matched controls, before and after 9 weeks of exercise training to test whether or not they could increase their aerobic fitness levels. The corrected cardiac lesions included tetralogy of Fallot, aortic stenosis, transposition of the great arteries and atrioventricular canal (AVC). Maximal exercise variables measured were heart rate (HR), oxygen consumption (VO2), and workload (stage of exercise and time on treadmill). The results of the pretraining tests indicated that the fitness levels of the 24 patients were significantly less than those of the controls. Of the original groups, 9 controls and 12 patients satisfactorily completed the training (jogging) program. The results of the post-training tests indicated that both the patients and controls significantly improved their fitness levels. Specifically, most subjects improved their maximal workload with little or no increase in maximal HR or VO2. In conclusion, children after open-heart surgery for complex congenital heart disease can further improve their work capacity by a dynamic exercise program. After training, they are able to do more work at a given VO2.