Abstract: Objective To explore the clinical value of Autostrain in evaluating changes in cardiac function in breast cancer patients before and after chemotherapy. Methods A total of 58 breast cancer patients who underwent postoperative chemotherapy with anthracycline drugs were selected. Conventional echocardiography and Autostrain strain analysis were performed before chemotherapy (T0), after chemotherapy (T1), and six months after chemotherapy (T2). The changes in cardiac function parameters at the three time points were compared. Results Compared with those at T0, left ventricular global longitudinal strain (LV-GLS), right ventricular free wall longitudinal strain (RVFWSL), right ventricular global longitudinal strain (RV4CSL), left atrial storage strain (LASR), and left atrial conduit strain (LASCD) were all significantly reduced at T1 and T2 (P<0.01). At T2, LV-GLS, LASR, LASCD, and RV4CSL were higher than those at T1. Only LV-GLS showed statistically significant differences (P<0.05), but its absolute value remained lower than before chemotherapy. Left atrial contraction strain (LASCT) at T1 was higher than at T0, but the difference was not statistically significant (P>0.05). There was no statistically significant difference in LASCT between T1 and T2 (P>0.05). Left ventricular end-diastolic diameter (LVIDd), left atrial anteroposterior diameter (LAD), left ventricular ejection fraction (LVEF), right ventricular diameter (RVD), and right atrial diameter (RAD) did not show statistically significant differences at the three time points (P>0.05). The tricuspid annular plane systolic excursion (TAPSE) and Tei index at T1 and T2 were significantly different from T0 (P<0.01), but there was no significant difference in TAPSE and Tei index between T1 and T2 (P>0.05). Conclusions After anthracycline chemotherapy, left atrial, left ventricular, and right ventricular functions all decrease in breast cancer patients. Strain parameters are superior to conventional echocardiography measurements in assessing early myocardial changes. Although LV-GLS improves at T2 compared to T1, it does not return to pre-chemotherapy levels. The application of Autostrain can detect early myocardial damage in the left atrium, left ventricle, and right ventricle caused by anthracycline chemotherapy in breast cancer patients, providing a diagnostic basis for early clinical intervention.