Evaluation Of Left Ventricular Systolic Function In Pediatric β-thalassemia Major By Myocardial Work

Background: Thalassemia is a kind of hereditary hemolytic anemia.According to the type of hemoglobin peptide chains deleted,thalassemia can be divided intoα-thalassemia,β-thalassemia,and other types of thalassemia.Due to iron overload of myocardium and high cardiac output,cardiac function of the patients would be abnormal.Sereve β-thalassemia patients may present with iron overload cardiomyopathy,arrhythmias,pulmonary arterial hypertension,and chronic heart failure.Irreversible damage of myocardium may occur in sereve cases.Speckle tracking echocardiography is a new method to evaluate left ventricular systolic function by quantifying myocardial work.Objective: This study aimed to assess the global longitudinal strain(GLS),global work index(GWI),global constructive work(GCW),global wasted work(GWW),and global myocardial work efficiency(GWE)by speckle tracking echocardiograhy,to evaluate the cardiac systolic function in children with beta-thalassemia major,and to explore the clincal value of myocardial work in monitoring cardiac function in sereveβ-thalassemia patients.Methods: A total of 91 thalassemia major cases diagnosed by genetic testing,including 37 thalassemia major cases who received hematopoietic stem cell transplantation in Shenzhen Children’s Hospital from August 2018 to August 2020 were selected in the study.According to the serrum ferritin level,TM patients were divided into high iron load group and low iron load group.Healthy children with body surface area(BSA)matched were selected as control group.The subjects were grouped as follows: 91 cases of TM group(91 cases of control group),34 cases of high iron load group(SF ≥ 2500ng/ml),32 cases of low iron load group(SF <2500ng/ml),37 cases of hematopoietic stem cell transplantation group.Clinical data such as height,weight and serum ferritin were measured for all cases.Echocardiography testing was performed using GE Vivid E95 system.Cuff sphygmomanometer was used to measure the brachial artery pressure of patients and controls.EchoPAC software was used to assess left ventricular systolic function and myocardial work.Results: Compared with normal group,GLS,GWI,GCW and GWE were decreased in TM group,the differences were statistically significant(P<0.05).Compared with low iron load group,GLS,GWI,GCW and GWE were decreased in high iron load group,GWW was increased in high iron load group.There were no statistically significant differences between low iron load group and high iron load group(P >0.05).Compared with the control group,GLS,GWI,GCW and GWE of the hematopoietic stem cell transplantation group were decreased,while GWW was increased,with statistical significance(P < 0.05).Compared with patients before transplantation,GLS,GWI,GCW,GWE were decreased after hematopoietic stem cell transplantation,GWE was increased,with no statistical significance(P>0.05).Conclusion: Left ventricular systolic function decreases in TM children in subclinical state.There are no differences in left ventricular systolic function in patients with different serum ferritin levels.Left ventricular systolic function decreases in patients after hematopoietic stem cell transplantation compared with healthy children.There are no differences in left ventricular systolic function in patients after hematopoietic stem cell transplantation.