Impact of cardiac rehabilitation on the exercise function of children with serious congenital heart disease.
OBJECTIVE
The exercise capacity of children with congenital heart disease (CHD) is often depressed. This depression is thought to be attributable to (1) residual hemodynamic defects and (2) deconditioning secondary to physical inactivity. We hypothesized that this latter component would be ameliorated by a formal cardiac rehabilitation program designed specifically for children. The objective of this study was to characterize the effect of a cardiac rehabilitation program on the exercise performance of children with CHD and to define the physiologic mechanisms that might account for any improvements that are observed.


METHODS
Nineteen patients with CHD who were referred for exercise testing and found to have a peak oxygen consumption (VO2) and/or peak work rate <80% of predicted were enrolled in the study. Sixteen patients (11 Fontan patients, 5 with other CHD) completed the program and had postrehabilitation exercise tests, results of which were compared with the prerehabilitation studies.


RESULTS
Improvements were found in 15 of 16 patients. Peak VO2 rose from 26.4 +/- 9.1 to 30.7 +/- 9.2 mL/kg per min; peak work rate from 93 +/- 32 to 106 +/- 34 W, and the ventilatory anaerobic threshold from 14.2 +/- 4.8 to 17.4 +/- 4.5 mL/kg per min. The peak heart rate and peak respiratory exchange ratio did not change, suggesting that the improvements were not attributable merely to an increased effort. In contrast, the peak oxygen pulse rose significantly, from 7.6 +/- 2.8 to 9.7 +/- 4.1 mL/beat, an improvement that can be attributed only to an increase in stroke volume and/or oxygen extraction at peak exercise. No patient experienced rehabilitation-related complications.


CONCLUSIONS
Cardiac rehabilitation can improve the exercise performance of children with CHD. This improvement is mediated by an increase in stroke volume and/or oxygen extraction during exercise. Routine use of formal cardiac rehabilitation may greatly reduce the morbidity of complex CHD.
Rhodes
Jonathan
J
Department of Pediatric Cardiology, Children's Hospital, Boston, Massachusetts, USA. jonathan.rhodes@cardio.chboston.org
Curran
Tracy J
TJ
Camil
Laurel
L
Rabideau
Nicole
N
Fulton
David R
DR
Gauthier
Naomi S
NS
Gauvreau
Kimberlee
K
Jenkins
Kathy J
KJ
D000293:Adolescent; D002648:Child; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006330:Heart Defects, Congenital / Q000503:physiopathology* / Q000534:rehabilitation* / Q000601:surgery; D006801:Humans; D008297:Male; D010865:Pilot Projects