Background and purpose: This study aimed to evaluate the effect of anthracyclines on left ventricular function in patients with breast cancer using two-dimensional speckle tracking imaging (2D-STI) combined with myocardial work. Methods: Thirty-five breast cancer patients who received anthracycline chemotherapy were prospectively enrolled in the study from Sep. 2019 to Mar. 2020 in Fudan University Shanghai Cancer Center. All the patients underwent traditional echocardiography and 2D-STI before and after the completion of two cures (160-180 mg/m 2 ) and four cures of the regimen (320-360 mg/m 2 ). The brachial artery cuff blood pressure was also obtained. The basic parameters of two-dimensional ultrasound were obtained and calculated

including left atrial diameter (LAD)

left ventricular end-diastolic diameter(LVEDD)

left ventricular end-systolic diameter (LVESD)

diastolic interventricular septal depth (IVSD)

left ventricular end-diastolic volume (LVEDV)

left ventricular end-systolic volume (LVESV)

left ventricular ejection fraction (LVEF)

early diastolic peak velocity (E)

late diastolic tissue velocity (a’) and early diastolic peak velocity/early diastolic tissue velocity (E/e’). The off-line EchoPac software was used to obtain left ventricular global longitudinal strain (GLS)

longitudinal strain of three‐layer myocardium (GLSendo

GLSmid

GLSepi)

global myocardial work index (GWI)

global constructive work (GCW)

global wasted work (GWW) and myocardial work efficiency (GWE). Results: Compared with those before chemotherapy

the GLSendo and GLS of breast cancer patients after two cycles of chemotherapy were reduced

but the difference was not statistically significant (P0.05); GWW increased while GWE decreased significantly after two cycles of chemotherapy (P0.05). After four cycles of chemotherapy

GLSendo

GWI

GCW and GWE decreased whereas GWW increased significantly compared with those at baseline and after two cycles of chemotherapy (P0.05). Compared with before chemotherapy

E/e’ increased after four cycles of chemotherapy (P0.05). There was no significant difference between the other echocardiographic parameters during the whole procedure (P0.05). Conclusion: 2D-STI can detect early changes of left ventricular function in breast cancer patients during anthracycline chemotherapy. GWW and GWE are more sensitive than other parameters.