Dynamic stress echocardiography in asymptomatic patients who received chemotherapy in childhood because of a malignant disease.

BACKGROUND: Introducing anthracycline antibiotics into the treatment of children's malignancies contributed enormously to the excellent outcome in children and adolescents. Nevertheless, the cardiotoxicity of such was discovered as early as in the 1970's. Only recently stress tests have been used to detect late cardiotoxic effects of anti-neoplastic drugs. AIM: To determine the function of the left ventricle (LV) in asymptomatic patients who were treated with chemotherapy containing anthracyclines in childhood or adolescence. METHODS: We examined 137 patients (81 men, 56 women), aged 16.6+/-4.8 years, in whom a malignant disease was diagnosed at the age of 9.1+/-4.8 years and who were treated with a cumulative dose of anthracyclines of 242+/-110 mg/m(2). The control group comprised 30 subjects (14 men, 16 women, mean age 19.5+/-5.2 years). The echocardiographic examination was carried out at rest and also immediately after a dynamic stress test. RESULTS: A decrease in the fractional shortening (FS) <30% was found in 11 (8%) patients. The values of ejection fraction (EF), mean velocity circumferential fibre shortening, end-systolic wall stress, excursion and systolic thickening of the LV posterior wall were significantly impaired in comparison with the group who had the FS > or =30% as well as with the control group. The maximal decrease in EF was reduced to 40% and FS - to 20%. The values of the index of the global function of LV were, in comparison with the control group, impaired in both subgroups of the patients. We did not find any differences in the exercise tolerance between the groups. The EF values both at rest and at stress were significantly lower in the group with FS <30% when compared with other groups. The values of percentage EF stress increment were increased in all the groups. A decrease in EF after exercise was not observed. CONCLUSIONS: Anthracycline chemotherapy leads to a late impairment of LV function. Asymptomatic patients with a decrease of EF to 40% or FS to 20% show preserved exercise tolerance as well as contractile reserve of the LV. These findings represent a better prognosis for the patient. Echocardiography at rest should be carried out repeatedly after the termination of the treatment and in the case of a pathological finding it is necessary to perform stress tests to evaluate the contractile reserve.