[Exercise tolerance in patients after acute lymphoblastic leukemia treatment in childhood]

The purpose of the presented study was to define the exercise tolerance in patients after acute lymphoblastic leukemia (ALL) treatment in childhood. Three groups of persons were examined: group A: 20 children, aged 7-19 years (mean 12.4 y), examined immediately after ALL therapy completion, with cumulative anthracycline (ATC) doses administered 155.8-300 mg/m2 and dexrazoxane, as cardioprotectant, group B: 36 patients, aged 12-24 years (mean 15.9), being 3-5 years after ALL treatment, who received ATC in cumulative doses 148.6-416.7 mg/m2, without cardioprotection, group C: 28 healthy volunteers, aged 9-25 years (mean 17.3), as controls. All the examined patients belonged to NYHA functional class I. In all subjects the exercise treadmill test was performed according to modified Bruce protocol. The parameters analysed were: MET--number of metabolic effort units achieved at the test, HRmax--maximal heart rate during exercise, %HRmax--percent of maximal HR for given patient's age achieved during the STdep--depression of ST segment in electrocardiography (ECG) immediately after the maximal exercise. During the exercise members of all 3 groups achieved the required HRmax without serious complaints and ECG abnormalities. Examined persons in group A,B and C presented with effort levels (MET), %HRmax, STdep that did not differ significantly. Only HRmax in groups A and C were higher than that achieved by members of group B.