The anthracycline doxorubicin, first introduced in the 1960's, continues to be an effectively utilized antineoplastic drug. Even at relatively low cumulative doses there is risk of cardiotoxicity. However, the incidence of subclinical cardiotoxicity is not known, carrying a potential risk for late effects in cancer survivors. Doxorubicin has systemic toxicity that may contribute to cardiac metabolic stress, but the main cardiotoxic mechanism involves cardiac mitochondria. The primary goal of this study is to detect early changes in the mitochondrial metabolism in situ as a marker for subclinical doxorubicin induced cardiotoxicity. The problem of cardiovascular complications following chemotherapy for breast cancer goes far beyond anthracyclines alone. In addition, other agents such as trastuzumab, and pertuzumab and emerging novel therapies may also promote cardiovascular injury. The secondary objective is to test the hypothesis that cardiotoxicity due to other medical anticancer therapies and radiation therapy involving the heart field is associated with a signature of early impaired aerobic cardiac metabolism through pyruvate dehydrogenase.