Normal values for cardiopulmonary exercise testing in children

Abstract

Background: A reference set of data of normal values of newly developed cardiopulmonary parameters of exercise testing in an 8-18-year-old population is lacking. Patients and methods: Cardiopulmonary exercise testing was performed in 175 healthy school children (8-18 years old). Continuous electrocardiography was performed, and minute ventilation, oxygen uptake (VO 2 ), and carbon dioxide (CO 2 ) production were measured continuously with a respiratory gas analysis system. Results: Peak VO 2 /kg did not change with age, whereas the ventilation to carbon dioxide exhalation slope was lower in the older children. The decline in heart rate during recovery was much faster in the youngest children. Linear regression analysis showed a significant effect of age on: peak work rate (WR peak ) and WR peak /kg, ventilation to carbon dioxide exhalation slope, heart rate recovery, and VO 2peak (boys only) (All P < 0.001). The ÁVO 2 /ÁWR slope remained constant throughout all age groups. Conclusion: This study comprehensively provides a reference set of data for the most important cardiopulmonary variables that can be obtained during exercise testing in children.

Reference values for cardiopulmonary exercise testing in children and adolescents in northwest Croatia

“…It also diff ers signifi cantly between males and females and depends on body mass. Cooper et al report on peak VO2 for 109 children that were not obese and were aged 6-17 years; peak VO2 W AT -work rate achieved at anaerobic threshold (AT); Wpeak -maximal work rate achieved (W); HR rest -resting heart rate in beats per minute measured after at least 3 min in sitting position before exercise testing; HRpeak -maximal heart rate at peak exercise (beats/min); HR reserve, maximal heart rateresting heart rate (beats/min); HR01 percentage, percentage heart rate recovery at 1 min (HRmax-HRpresent)/(HRmax-HRrest)*100%; HR02 percentage, percentage heart rate recovery at 2 min (HRmax-HRpresent)/(HRmax-HRrest)*100%; RERpeak -maximal respiratory exchange ratio; VO2AT -oxygen uptake at anaerobic threshold (mL/kg per min); VO2 percentage AT, (VO2 at anaerobic threshold/VO2max)*100%; VO2peak -maximal oxygen uptake (mL/kg/min); VO2/HR oxygen pulse at rest -anaerobic threshold and peak exercise expressed in mL; sysRR at rest -peak and 4 minute recovery, BF -breathing frequency at rest, anaerobic threshold and peak exercise in breaths per minute, VT -tidal volume in L at rest, anaerobic threshold and peak exercise, VE -minute ventilation in L per minute at rest, anaerobic threshold and peak exercise, VE/VO2 slope of respiratory minute volume to VO2 uptake at AT and peak exercise; VE/ VCO2, slope of respiratory minute volume to CO2 production; VD/VT -dead space ventilation at anaerobic threshold and peak exercise, PETCO2 -end-tidal CO2 at anaerobic threshold and peak exercise; *p<0.001 for diff erence between boys and girls correlated similarly with either weight or height and gave predicted equations for boys and girls, which are quite similar to the values we found (3,6,7). At the time when reduction in physical activity along with obesity in children has become apparent worldwide, these fi ndings together with the fact that just two children had to be excluded because of overweight (>95 percent BMI) with mean BMI 20.5±3.6 kg/m 2 are still encouraging.…”

“…On the other hand, each laboratory should have its own reference set of values. Moreover, published reference values might not be representative for today's children (2)(3)(4)(5)(6). To obtain reference data for exercise testing in healthy children and adolescents in Croatia, we investigated CPET results of 164 Croatian school children coming from the northwest part of Croatia, with an age range of 11-17 years.…”

“…Additional ventilatory control parameters during exercise in children are minute ventilation (VE), assessment of anaerobic threshold (AT), respiratory compensation point (RCP), oxygen uptake (VO2), carbon dioxide output (VCO2), ventilatory equivalents for carbon dioxide and oxygen (VE/VCO2, VE/VCO2), oxygen pulse (VO2/HR), physiological dead space-tidal volume ratio (VD/VT), end-tidal pCO2 (PETCO2), end-tidal pO2 (PETO2), gas exchange ratio (R), the increase in oxygen uptake in response to a simultaneous increase in work rate (ΔVO2/ΔWR), breathing reserve (BR), and heart rate reserve (HRR) (1). Normal values for CPET are already published and represent a set of normal values for specifi c population coming from specifi c region with diff erent anthropometric and cultural characteristics (2)(3)(4)(5)(6). On the other hand, each laboratory should have its own reference set of values.…”

“…Children's cardiovascular responses during exercise testing present diff erent characteristics, particularly oxygen uptake, lower arterial partial pressure of carbon dioxide (PaCO2) set-point during exercise, resulting in greater ventilatory effi ciency (the relationship of the liters of ventilation required to eliminate a liter of CO2) VE/VCO2 in younger population, heart rate and blood pressure response, which are essential in interpreting respiratory and hemody-namic data (1)(2)(3)(4)(5)(6)(7)(8). Diseases that are associated with myocardial ischemia are rare in children (8).…”

Reduction of exercise capacity in children from summer to winter is associated with lower sporting activity: a serial study

“…Regarding reference values for the exercise performance, expressed as VO 2 , in children there are few studies published (24)(25)(26). Today, large-cohort data are not available for children.…”