 Anthracycline cardiotoxicity is characterized by ventricular remodeling and progressive cardiac dysfunction. Since ventricular remodeling in other types of heart failure can be treated effectively with an angiotensin-converting enzyme inhibitor ACEi, these agents would appear a logical therapy in children with anthracycline-induced heart failure. Previous experience with ACEi in childhood cancer survivors has shown mixed results, possibly due to the fact that treatment is initiated too late in the natural history of the disease. Providing treatment in childhood cancer survivors with early signs of cardiac remodeling may be more effective than treating children who have global dysfunction. The benefits of early intervention are unclear, so it is unclear whether CCS and their parents will be willing to receive treatment where the target outcome prevention of decreased global function or congestive heart failure may not occur for years after the intervention. Assessing the feasibility of this pre-emptive approach is the primary aim of the study. 