Prevention of Anthracycline or Trastuzumab Induced Cardiomyopathy by Metoprolol

The primary objective of this study is to investigate whether giving prophylactic metoprolol prior to and during anthracycline or trastuzumab therapy will decrease the incidence of anthracycline-induced cardiomyopathy. Patients are randomized to receive metoprolol or no treatment prior to anthracycline or trastuzumab treatment. The ejection fraction, as measured by nuclear ventriculography is measured before and after treatment.