Bergamini C, et al. - Researchers assessed the link between left atrium (LA) volume index (LAVI) change over time and the development of trastuzumab-related cancer therapeutics related cardiac dysfunction (CTRCD) among retrospectively included consecutive HER-2 positive breast cancer (BC) patients. These subjects underwent transthoracic echocardiography before beginning trastuzumab and at every 3 months for 12 months. Using the modified Simpson's rule, LA volume was measured and indexed for body surface area. Findings demonstrated an association of trastuzumab-related CTRCD with significant LAVI morphological remodeling in BC patients.