Speckle Tracking Layer-specific Strain Technology In Evaluation Of Effect Of Anthracycline-induced Cardiotoxity On Left Ventricular Myocardial Strain In Breast Cancer Patients

Objective : As one of the effective methods for tumor therapy,chemotherapy has significantly improved the prognosis and long-term survival rate of patients.Anthracycline chemotherapy drugs are commonly used in clinical,these drugs are various and widely used in the adjuvant treatment of cancers,especially in the breast cancer.However,anthracycline chemotherapeutic drugs have potential myocardial toxicity,and myocardial toxicity is one of the most serious side effects of this drug,which can be irreversibility and seriously affect the patient's survival and quality of life.Therefore,it's very important to detect and prevent the cardiotoxicity of this chemotherapy drugs.This experiment is aimed at discussing the changes in the longitudinal systolic function of the left ventricular myocardium in patients after breast cancer surgery with anthracycline chemotherapy using speckle tracking layer-specific strain technology,by this means to evaluate and suggest the myocardial toxicity of anthracycline chemotherapy drugs,so as to timely adjust the chemotherapy regimen and improve the clinical outcome of breast cancer patients.Methods : This experiment randomly selected 60 patients who needed chemotherapy after breast cancer surgery and without heart related primary disease as chemotherapy group,the chemotherapy regimens of these patientswere TAC(Taxotere,Anthracycline,Cyclophosphamide),the chemotherapy cycle of each patient were divided into four stages: the stage before chemotherap(T0),the stage after the second chemotherapy(TI),the stage after the fourth chemotherapy(TII)and the stage after the sixth chemotherapy(TIII).On the 20 th day after every chemotherapy's finish,the conventional echocardiography parameters were recorded from the apical four-chamber view and long-axis view firstly,then the high frame frequency dynamic two dimensional images were recorded from the apical four-chamber view,two-chamber view and long-axis view of the left ventricle during three consecutive cardiac cycles.In addition,34 healthy women were selected to obtain the conventional echocardiography parameters and same views as control group.The workstation named Echo PAC was used for offline analysis and the endocardial contour was described,the longitudinal strain(LS)of myocardium were measured in endocardium,midmyocardium and epicardium,and the longitudinal strain of myocardial basal segment,middle segment and apex segment of each layer were also acquired,then mean values were calculated.Results:(1)The conventional echcardio graphic parameters of LVDd,LVDs,IVSTd,PWTd,E peak,A peak,E/A and LVEF had no significantly difference between T0 and the control group(P>0.05).(2)The conventional echcardio graphic parameters of IVSTd,PWTd,E peak,A peak,E/A among the chemotherapy groups had no significant difference(P>0.05);Theparameters of LVDd,LVDs and LVEF between TIII and T0 had significantly difference(P<0.05),but there had no difference between TII,TI and T0(P>0.05).(3)In the apical four-chamber,two-chamber and long-axis views of control group and chemotherapy groups,LS of endocardium was higher than LS of midmyocardium,and LS of midmyocardium was higher than LS of epicardium,the LS of three myocardial layers in the three views decreased from the inside to the outside gradully(P<0.05).(4)LS of apical four-chamber,two-chamber and long-axis views of epicardium among chemotherapy groups had no significant difference(P>0.05),LS of these three views of midmyocardium among chemotherapy groups had no significant difference(P>0.05).(5)In the apical four-chamber,two-chamber and long-axis views,compared with LS of endocardium among chemotherapy groups,TI and T0 had no significant difference(P>0.05),LS of endocardium among other chemotherapy groups had significant difference(P<0.05),and LS of TIII was the lowest.(6)In both control group and chemotherapy groups,from basal segment to apex segment the LS of endocardium,midmyocardium and epicardium increased gradually,the difference of each two had statistically significant(P<0.05).(7)There was no significant difference of the apex segment's LS among the chemotherapy groups(P>0.05).In addition to TI,there were significant differences between TIII,TII and T0 in the LS of basal and middle segment.(8)Compared with T0,the strain curve's morphology and trend of TIII were more disorganized,and the peak time consistency was poor.Conclusions : 1.The layer-specific strain technology is simple,reproducible and of no angle dependence quantitative,it can evaluate changes of left ventricular strain accurately and determine inflection point of patients postoperative breast cancer with anthracycline-based chemotherapy,in order to avoiding the irreversible damage of excessive anthracycline-based drugs application.2.Anthracyclines' myocardial toxicity mainly occcurs in the endocardium and have dose accumulation effect.