Effect of Anthracycline Chemotherapy on Cardiac Toxicity and Evaluation of Two-Dimensional Speckle Tracking Imaging in Breast Cancer

To investigate the cardiac toxicity of anthracycline chemotherapy in patients with breast cancer and the effect of two-dimensional speckle tracking imaging technology. In this study, 83 patients with breast cancer were selected as the research objects and divided into the study group (n=43) and the control group (n=40) according to whether anthracycline was included in the chemotherapy regimen. The control group was treated with paclitaxel for 4 w, and the study group was treated with epirubicin (anthracycline) for 4 w and paclitaxel for 4 w. The treatment course was 4 cycles. The changes of peak strain dispersion, global longitudinal strain and left ventricular ejection fraction of patients before and after chemotherapy were examined by two-dimensional speckle tracking imaging and other techniques. The left atrial diameter, left ventricular end diastolic diameter, left ventricular end systolic diameter early to late mitral inflow velocity early diastolic mitral annular velocity (E), the ratio of early diastolic mitral inflow velocity to early diastolic annular velocity (E/e), the changes of myocardial enzymes and N-terminal pro-brain natriuretic peptide were observed. Before chemotherapy, there was no difference in the measured values of left atrial diameter, left ventricular end diastolic diameter, left ventricular end systolic diameter, E/A and E/E’ between the study group and the control group (p>0.05). After chemotherapy, there was still no statistically significant difference in these values (p>0.05). Before chemotherapy, the values of left ventricular ejection fraction, global longitudinal strain, global longitudinal strain-A4C, global longitudinal strain-A3C, global longitudinal strain-A2C, and peak strain dispersion between two groups were not statistically significant (p>0.05). After chemotherapy, the measured values of global longitudinal strain, peak strain dispersion, global longitudinal strain-A3C, global longitudinal strain-A2C in the study group were lower than those in the control group, with statistical significance (p<0.05), while the measured values of global longitudinal strain-A4C were not significantly different between two groups (p>0.05). Before and after chemotherapy, there was no significant difference in creatine kinase, lactate dehydrogenase and NT-proBNP between the study group and the control group (p>0.05). Breast cancer patients treated with anthracyclines accompanied by targeted drug chemotherapy have obvious toxicity to left ventricular function and two-dimensional speckle tracking imaging can detect these changes more sensitively than conventional cardiac ultrasound.