Exercise echocardiography reflects cumulative anthracycline exposure during childhood

Low and moderate dose anthracycline therapy used in current treatment protocols, may be associated with subclinical abnormalities of cardiac function and late presentation with congestive heart failure. Exercise echocardiography is a useful and non-invasive means of uncovering latent cardiac dysfunction in other settings. The purpose of this study is to determine whether exercise echocardiography has the potential to detect subclinical abnormalities of cardiac function in children treated with anthracyclines.

One hundred ten children previously treated with anthracycline, in remission and off treatment for >12 months were assessed, together with 31 control subjects. Each subject had a resting ECG and echocardiogram performed, and following exercise on a treadmill according to the Bruce protocol, a repeat echocardiogram was performed.

Cumulative anthracycline dose was the only patient variable related to any of the outcome measures. Resting fractional shortening was normal in the majority of treated patients but was inversely related to cumulative anthracycline dose (rate of decline 1.2%/100 mg/m(2)). Following peak exercise, the inverse relationship between fractional shortening and anthracycline dose was more pronounced (rate 2.7%/100 mg/m(2)).

Higher anthracycline doses are associated with a greater difference in peak fractional shortening between treated subjects and controls. Exercise echocardiography is a simple, relatively inexpensive tool that may enhance the detection of latent cardiac dysfunction after anthracycline administration during childhood.