Functional myocardial impairment in children treated with anthracyclines for cancer.

A non-invasive exercise method was used to look for myocardial damage in apparently normal children who had received moderate doses of anthracyclines for treatment of cancer. 19 children (mean [SD] age 10.6 [4.3] years) who had received anthracyclines (mean total dose 230 [119] mg/m2) and 10 who had received other cytotoxic drugs (mean age 13.3 [4.9] years) were selected from 263 children attending routine follow-up examinations. They underwent measurement of heart rate, blood pressure, and left ventricular dimensions by echocardiography before and after exercise on a bicycle for a maximum of 10 min. All 29 were in remission. All the subjects showed normal fractional shortening (FS = left ventricular end-diastolic minus end-systolic diameter as a percentage of the end-diastolic diameter) at rest, but the increase in FS on exercise was significantly lower in the children who had received anthracyclines than in those who had not (3 [16]% vs 23 [17]%; p less than 0.05). This difference remained significant after adjustment for age and drug exposure. However, there were no significant differences between the groups in the adjusted mean percentage changes on exercise in heart rate or systolic or diastolic blood pressure. Disease type had no effect on the cardiological indices. Thus, many children who have received anthracyclines may have suffered subclinical myocardial damage. Post-exercise echocardiography seems a useful non-invasive method for detecting such damage. Long-term cardiological follow-up of these patients is needed.