 - Sub-study B trastuzumab: In addition to the assessments performed in the primary study, patients undergo some extra tests. Patients undergo an additional visit after the third treatment of trastuzumab approximately 6 months after the first dose of doxorubicin hydrochloride, during which patients have blood samples collected and analyzed as in Primary study visit 2. HRV is measured and, if necessary, a transthoracic echocardiogram is performed. 