Cardiac output response to dynamic exercise after atrial switch repair for transposition of the great arteries.

Results from this study showed that patients who underwent successful operation for transposition of the great arteries had no appropriate increase in stroke volume in response to exercise of a nature similar to common recreational activities. The impairment, most likely due to disturbances in both venous return and ventricular systolic function, is compensated for by an increase in peripheral oxygen extraction; however, this increase may not be adequate with maturation or during prolonged exercise when cardiovascular constraints are more important.

[Cardiac output evaluation during exercise in children treated with atrial surgery for transposition of great vessels]. / Evaluation du débit cardiaque à l'exercice chez des enfants traités par chirurgie atriale d'une transposition des gros vaisseaux.

The long-term physiopathological consequences of atrial surgery (Senning or Mustard procedures) for transposition of the great vessels with respect to exercise capacity are not well known. We measured the cardiac index by the technique of CO2 rebreathing at two submaximal levels of exercise corresponding to a stable oxygen consumption of 20 (E20) and 30 (E30) ml/min/kg in 7 patients successfully operated for transposition of the great vessels and in 7 control children paired for age, gender and body surface area. Despite an identical chronotropic response to exercise in the two groups, the increase in cardiac index was not as great in the children operated for transposition (from 6.86 +/- 0.51 to 7.71 +/- 0.78 l/min/m2) as in the control population (from 7.71 +/- 0.78 to 10.2 +/- 0.51 l/min/m2; p < 0.02). The stroke volume index was therefore significantly lower in the transposition group at both levels of exercise (52 +/- 3.2 vs 63 +/- 4.1 ml/m2; p < 0.04 at E20; and 46.4 +/- 4.3 vs 66 +/- 5.1 ml/m2 at E30). The main cause of this reduction of the stroke volume index is probably a lack of adaptation of right ventricular systolic function on exercise but it is not possible to exclude diastolic dysfunction due to reduce compliance secondary to the intraatrial patch. The conditions of preload are in fact instrumental in increasing stroke volume index at submaximal exercise levels.

Back pain and spinal alignment abnormalities in schoolchildren.

OBJECTIVES: To study the prevalence of back pain and spinal alignment abnormalities in children aged 10 to 14 years; to define subsets of subjects with similar clinical profiles; and to identify factors associated with pain in the thoracic or lumbar spine. PATIENTS AND METHODS: 972 five- and nine-graders completed a back pain questionnaire at school and were examined by a school physician for spinal alignment abnormalities and for motion range limitation in the spine and/or lower limbs. Multivariate analysis was used to define clinical subsets and to identify factors associated with back pain. RESULTS: The point prevalence of back pain increased with age, from 14.3% in the ten-year-olds to 24% in the 14-year-olds. Girls were more likely than boys to report back pain, which was usually located in the low back. The prevalence of scoliosis increased with age and was higher in the girls. Multivariate analysis identified five clinical profiles: no spinal pain; nonserious spinal pain with no impact on medical service utilization or physical activities; spinal pain unrelated to an injury; injury-related spinal pain not treated by drugs or physical therapy; and injury-related spinal pain treated by drugs and physical therapy. Several factors associated with spinal pain were identified, with variations across the five groups.