Measurement and validity of the ventilatory threshold in patients with congenital heart disease

Pediatr Cardiol. 1996 Jan-Feb;17(1):7-14. doi: 10.1007/BF02505805.


The purpose of the present study was to measure oxygen uptake (VO2) at the ventilatory threshold (VT) in patients with congenital heart disease using a progressive exercise protocol on a treadmill and to evaluate the validity and feasibility of this procedure. Eight control subjects and seventeen patients performed a maximal exercise test with breath-by-breath measurement of ventilation and gas exchange variables. VT(VE) was determined by the change in the ventilatory equivalent for VO2 and carbon dioxide output, VT(V-sl) by the V-slope method, and the lactate threshold (LT) by the change in blood lactate concentration; these parameters were determined in 100%, 88%, and 96% of subjects, respectively. The interobserver error among three evaluators was not significant, and LT was correlated with each VT (r = 0.97, 0.92; p = 0.0001) and with peak VO2 (r = 0.91; p = 0.0001). The VTs were correlated with each other when expressed as milliliter per minute and milliliters per kilogram per minute. It was concluded that a progressive exercise protocol on a treadmill was a feasible procedure for determining the VTs in most individuals and that VTs were valid, useful parameters for evaluating submaximal exercise tolerance in patients with congenital heart disease.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Adolescent
  • Adult
  • Anaerobic Threshold*
  • Analysis of Variance
  • Blood Gas Analysis
  • Child
  • Exercise Test / methods
  • Exercise Tolerance / physiology*
  • Female
  • Heart Defects, Congenital / physiopathology*
  • Humans
  • Lactates / blood
  • Linear Models
  • Male
  • Observer Variation
  • Oxygen Consumption
  • Pulmonary Gas Exchange
  • Reproducibility of Results


  • Lactates