Late cardiotoxicity of anthracyclines in children with acute leukemia.

Congestive heart failure is one the most severe late complications of cancer therapy with anthracyclines. The function of the heart muscle was evaluated in 50 children (30 boys and 20 girls), aged from 5 years 6 months to 20 years 7 months, treated in the past for lymphoblastic or nonlymphoblastic acute leukemia. The total dose of the administrated anthracyclines was 120-550 mg/m2. The circulatory system was evaluated on the basis of history, physical examination, ECG, exercise test and echocardiography. Impaired contractility of the heart muscle was found in 32% of cases. The degree of impairment was related to the total dose of anthracyclines and to the period from discontinuation of therapy. Heart muscle function disorders were present also in children, in whom the cumulative dose of anthracycline antibiotics did not exceed 400 mg/m2. In the majority of patients the evidence of heart damage was subclinical.