Evaluation Of Systolic Dysfunction Of Left Ventricular In Thalassemia Major Children By Velocity Vector Imaging Technique

Objective:To analyse the systolic function features of left ventricular in normal childrenand analyse the systolic dysfunction of left ventricular in thalassemia major childrenby using velocity vector imaging(VVI)technique.Methods:General echocardiography were done in40normal children and80thalassemiamajor children.Patients were divided into two groups: thalassemia A, serum ferritin(SF)＜2500μg/L,40cases; thalassemia B, SF≥2500μg/L,40cases. Thefollowing parameters will be meansured by VVI software:1. the basal,middle andapical segment of endocardium and epicardium longitudinal peak systolicvelocity(LV),displacement (LD),strain(LS) and strain rate(LSR) of left ventricular;2. the basal,middle and apical level of endocardium and epicardium radial peaksystolic velocity(RV),displacement (RD),strain(RS) and strain rate(RSR) of leftventricular;3. the basal,middle and apical level of endocardium and epicardiumcircumferential peak systolic strain(CS) and strain rate(CSR) of left ventricular.Results:1. There was a certain regular pattern in the VVI parameters of normal group:①the endocardium and epicardium longitudinal peak systolic velocity,displacement,strain and strain rate of left ventricular were basal＞middle＞apicalsegment; the differences in each segment of LV,LD was greater than the differencesin each segment of LS,LSR.②the endocardium and epicardium radial peak systolic velocity,displacement,strain and strain rate of left ventricular were middle＞basal＞apical level; thedifferences in each level of RS,RSR was greater than the differences in each level ofRV,RD.③the endocardium and epicardium circumferential peak systolic strain andstrain rate of left ventricular were apical＞middle＞basal level;the differences in eachendocardium level of CS,CSR was greater than the differences in each epicardium level of CS,CSR.2. The general VVI parameters in three derection of epicardium were low thanthose of endocardium in the normal group (P＜0.05).3. There were no significant differences between thalassemia A,B and normalgroups about the measurements from general echocardiography and the LV mass(P＞0.05).4. Compared with normal group, the longitudinal,radial and circumferentialpeak systolic VVI parameters were all changed:①the most of segment and general longitudinal peak systolic VVI parameters,the most of level and general circumferential peak systolic VVI parameters of groupthalassemia B were reduced, but each level and general radial peak systolic VVIparameters of group thalassemia B were increased(P＜0.05); the most of segment andgeneral LSR,the most of level and general CS,CSR of group thalassemia A werereduced,but the most of level and general RS and RSR of group thalassemia A wereincreased(P＜0.05).②the differences in sectional,level and general VVI parameters between groupthalassemia B and normal group(P＜0.01) were greater than the differences betweengroup thalassemia A and normal group(P＜0.05),the part segment,level and generalVVI parameters between group thalassemia A and B had statistical difference(P＜0.05).③the longitudinal VVI parameters were reduced obviously in the basal segmentand the circumferential VVI parameters were reduced obviously in the apical level inthe group thalassemia A.④the differences in the part of segment,level and general LSR and CSR(P＜0.01) were greater than the differences in the other VVI parameters(P＜0.05) beweenthe group thalassemia B and normal group.⑤the endocardium and epicardium VVI parameters were all changed in groupthalassemia (mainy to group thalassemia B),the differences beween each segmentand general LSR of endocardium and these of normal group(P＜0.01) were greaterthan the differences between each segment and general LSR of epicardium and theseof normal group(P＜0.05). Conclusion:1. There is a certain regular pattern in the longitudinal,radial and circumferentialVVI parameters of normal children, longitudinal VVI: basal＞middle＞apicalsegment; radial VVI: middle＞basal＞apical level; circumferential VVI: apical＞middle＞basal level. The general VVI parameters in three derection of endocardiumare greater than those of epicardium in the normal children.2. VVI could be used to noninvasively and accurately assess of left ventricularsystolic function in three direction (longitudinal,radial and circumferential direction)of thalassemia major children. VVI could detect the systolic dysfunction of leftventricular in thalassemia major children which was difficult to be deceted by generalechocardiography:①The systolic function of left ventricular in thalassemia major children withnormal ejection fraction is in subclinical reduction phase;②The systolic dysfunction of left ventricular in group B with higher level SF ismore serious than that in group A with lower level SF.③The systolic dysfunction in the segment of which myocardial movementstrength is strong is early.④The strain rate is more sensitive to reflect the systolic dysfunction of leftventricular than the velocity,displacement and strain.⑤The systolic dysfunction of left ventricular is presented in endocardium andepicardium without exception.The systolic dysfunction of left ventricular inendocardium is more serious than that in epicardium.