Early detection of anthracycline cardiotoxicity in children with acute leukemia using exercise-based echocardiography and Doppler echocardiography.

We performed both supine bicycle ergometer (BEx) and hand-grip (HGx) exercise tests to evaluate cardiac function in 13 asymptomatic children with leukemia who had completed a general treatment protocol. We calculated fractional shortening (FS), end-systolic stress-volume index (ESS/ESVI), left ventricular diastolic filing velocity ratio (A/E) and normalized peak rate of diastolic increase in left ventricular internal dimension (dLVDt/dt/LVDt). Before the exercise, we found that dLVDt/dt/LVDt was decreased in the high-dose anthracycline group (anthracycline cumulative dose of 480-570 mg/m2), even though other cardiac function parameters were not different from those in the control. In BEx, the percent change in ESS/ESVI decreased in an anthracycline cumulative dose-dependent fashion. In HGx, ESS/ESVI showed a decreased response only in the high-dose anthracycline group. Therefore, we conclude that: 1) the diastolic function parameter dLVDt/dt/LVDt might show abnormalities prior to other systolic function parameters, 2) the percent change in ESS/ESVI in BEx is the most sensitive parameter studied, and could detect cardiac function abnormalities even in the small-dose anthracycline group (anthracycline cumulative dose of 175 mg/m2), and 3) BEx is more suitable for the early detection of anthracycline cardiotoxicity than HGx.