Ability of L-carnitine to Prevent Heart Damage in Breast Cancer Patients Receiving Anthracycline Chemotherapy

Breast cancer is very common and afflicts 1 in 9 North American women. The treatment of breast cancer often requires the use of chemotherapy including "anthracyclines". Anthracyclines can damage the heart resulting in heart failure and even death. Clinicians and researchers are continually seeking methods that will reduce the toxic effects of anthracycline treatment. L-carnitine is a substance that is produced naturally in the body and is required for normal heart function. Animal studies have suggested that L-carnitine protects the heart from the effects of anthracyclines, however this has not been verified in humans. This study will assess the potential role of L-carnitine in the prevention of anthracycline induced heart damage. The investigators will enroll 144 patients into this study. Patients will be randomly assigned to L-carnitine therapy or to standard care (no L-carnitine therapy). Patients in the L-carnitine group will receive oral and intravenous L-carnitine prior to and after their anthracycline therapy. Patients will undergo regular follow up and testing to assess heart function. The investigators believe that patients treated with L-carnitine will benefit and have fewer complications associated with anthracycline treatment.