Hemodynamic responses to supine exercise in children with left-sided cardiac disease

[Cardiovascular evaluation in athletic children]

Although rare, sports related sudden cardiac deaths in children and adolescents justify the search for risk factors in any child or adolescent who wishes to practice sports. Each time that history and careful clinical cardiovascular examination point to a possible cardiovascular abnormality, an electrocardiogram and an echocardiography must be performed. Exercise testing is useful to appreciate the cardiovascular tolerance, either in normal subjects or in subjects with a cardiovascular abnormality; its interpretation requires good knowledge and understanding of hemodynamic responses to exercise. Indications, risks and procedures of exercise testing are discussed with reference to exercise physiology.

Treadmill exercise in Neopolitan children and adolescents

Two hundred and eighty healthy children from Naples, Italy (140 boys and 140 girls) aged 4-17 years were studied using Bruce walking treadmill protocol to voluntary exhaustion. Endurance time and double product increased with age. Systolic blood pressure increased linearly during the test. Multivariate analysis showed that body weight and age were the best predictors of endurance time. Endurance time averaged 15.2 +/- 2.8 min in boys and 13.7 +/- 2.3 min in girls (p = 0.00001). Mean +/- SD double product at peak exercise was 264.3 +/- 63 (boys) and 242 +/- 44 (girls) (p = 0.01). Sinus arrhythmia was present in 78% of the children and disappeared at a mean heart rate of 112 +/- 16 beats/min during exercise. The voltage of the R wave on V4 lead decreased in all but four children during the test (delta R = -0.25 +/- 0.24 mV). The P and T waves increased in almost all children. No ST depression or upward sloping was detected. The voltage of the PR isoelectric line remained constant. The J point was displaced downwards in 78% of children, unchanged in 11% and displaced upwards in the remaining 11% of the children. The present study gives reference parameters for a walking treadmill test in Southern European children.