Cardiopulmonary Evaluation of Exercise Tolerance After Chest Irradiation and Anticancer Chemotherapy in Children and Adolescents

OBJECTIVE: The aim of the study was to evaluate the cardiopulmonary exercise tolerance in children and adolescents after chest irradiation and anticancer chemotherapy. METHODS: We studied 30 subjectively asymptomatic patients aged 8 to 25 years treated for pediatric malignancies with chest irradiation (XRT) +/- chemotherapy. The median interval since XRT was 7 (range, 2 to 13) years. The median XRT dose for mediastinum and/or lungs was 2550 (range, 1000 to 5100) cGy. The median cumulative dose of anthracyclines was 250 (range, 0 to 480) mg/m2. Cardiac function and exercise tolerance were evaluated by electrocardiography, echocardiography, radionuclide cineangiography, and exercise test with gas exchange analysis. RESULTS: The patients differed from normal controls in systolic indices of myocardial function. In echocardiography, the left ventricular contractility was abnormal in 14/30 patients. In radionuclide cineangiography, the left ventricular ejection fraction was subnormal in 6/30 patients, and in 9/30 patients the rise in ejection fraction during exercise was inadequate (< 5%). In exercise testing, the mean (+/- SD) maximum workload attained was 2.7 (+/- 0.7) watts/kg, and the mean (+/- SD) maximum oxygen consumption was 35.4 (+/- 9.7) mL/min/kg. Both variables were < 80% of predicted values in 11 patients. CONCLUSIONS: XRT and anticancer chemotherapy very often lead to late cardiopulmonary toxicity and impaired exercise tolerance. Although in most cases this toxicity seemed to be mild and subclinical, the long-term clinical sequels merit further evaluation.