ISSN:
1432-1971
Keywords:
Exercise
;
Congenital heart disease
;
Anaerobic metabolism
;
Physical performance capacity
;
Pulmonary ventilation
;
Ventricular septal defect
;
Atrial septal defect
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The ventilatory response to graded treadmill exercise was studied in 50 children with congenital heart disease (CHD), a left-to-right intracardiac shunt, and compared to that of age and sex-matched healthy children. In all these children, a breakpoint in the minute ventilation $$(\dot V_E )$$ in relation to increasing oxygen uptake $$(\dot VO_2 )$$ was detected. Because of the reported coincidence of the nonlinear increase in $$\dot V_E $$ and lactate with increasing $$\dot VO_2 $$ , this threshold has been named “ventilatory anaerobic threshold” (VAT), expressed in ml O2·min−1·kg−1. VAT correlated well with $$\dot VO_2 $$ (ml·min−1·kg−1), reached at a heart rate of 170/min $$(\dot VO_{2,170} )$$ . Compared to normal children, however, a significantly (p〈0.05) larger percentage (56%) of the patients showed a subnormal value (below the 95% confidence limit) for VAT than for $$\dot VO_{2,170} $$ (28%). Furthermore, when expressed as a percentage of the mean normal value, the mean VAT (89±14.4% SD) was significantly (p〈0.05) lower than the mean $$\dot VO_{2,170} $$ (103±17.2%). VAT (ml O2·min−1) correlated significantly with body weight and height, even after adjusting for age, and with the percentiles of body weight and height. VAT constitutes a useful noninvasive criterion for evaluating exercise performance in children with CHD, at least those forms with a left-to-right intracardiac shunt, and it is significantly more sensitive than the $$\dot VO_{2,170} $$ in detecting decreased cardiorespiratory endurance capacity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02315477
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