(r=-0.672，P<0.05).Conclusion：The regional cardiac dysfunction mainly takes place in the left lateral wall prior to the onset of global cardiac dysfunction in β-thalassemia major patients.QTVI and SRI both can detect regional systolic dysfunction in the early stage.The systolic strain rate in basal segment of LV lateral wall(LV-SRs)has a good correlation with blood transfusion accumulation dose.It is a valuable parameter in early diagnosis of cardiac systolic dysfunction in β-thalassemia major patients.

    【Key words】 Quantitative tissue velocity imaging; Strain rate imaging; Echocardiography; β-thalassemia; Cardiac function

    First-author’s address：Shenzhen Children’s Hospital ......