Several breast cancer therapies can lead to cardiovascular toxicity: drugs such 
anthracyclines can cause permanent damage, anti-HER2 agents may cause transitory 
and reversible cardiac dysfunction and others, such as those used in endocrine 
therapy, primarily disturb lipid metabolism. Considering the seriousness of 
these complications, trials are now being conducted to address cardiotoxicity 
associated with new drugs; however, to fully understand their toxicity profiles, 
longer follow-up is needed. In this review, we compile the information available 
about cardiac toxicity related to well-established systemic breast cancer 
treatments, as well as newer drugs, including antiangiogenics, mTOR inhibitors 
and novel anti-HER2 agents. We also describe current and next generation cardiac 
biomarkers and functional tests that can optimize treatment and reduce and 
prevent the incidence of treatment-related cardiotoxicity.