Sequential equilibrium gated radionuclide angiocardiography for the detection of doxorubicin cardiotoxicity

Right and left ventricular ejection fractions (RVEF and LVEF) were studied at rest, during exercise, and in the immediate post-exercise period (recovery) in 23 patients treated with doxorubicin. Ejection fractions were determined using equilibrium gated radionuclide angiography and non-interactive computer processing. Two effects of doxorubicin emerged: (1) The LVEF at rest and the maximal LVEF reached during the stress test decreased as a function of the cumulative dose expressed in mg/m2. (2) When two measurements were performed before and after an interval dose of less than 100 mg/m2, the resting and maximal LVEF showed an increase, but at higher interval doses, those values showed a decrease. In general, the effect of an incremental dose was not a function of the cumulative dose. No significant changes were detected in RVEF, and LVEF at standardized exercise levels did not correlate with cumulative doses or change as a function of interval dosage.