Quantitatively Assess Left Ventricular Longitudinal Function By Velocity Vector Imaging In Kawasaki Disease

Backgroud:Kawasaki disease(KD) is an acute,self-limited vasculitis syndrome of unknown etiology that occurs predominantly in infants and young children, and there is a 20-25%chance of serious cardiovascular damage if the treatment is not given early in the course of the disease, it may develop persistence coronary-artery aneurysms or stenosis,and might subsequently lead to ischemic heart disease or myocardial infarction and even sudden death.KD has replaced rheumatic fever as the primary cause of children's acquired heart disease. Thus, to make a correct assessment of left ventricular regional myocardial function is essential to the prognosis of Kawasaki disease.Recently developed new technique-Velocity Vector Imaging (VVI) can conquer the drag of surrounding myocardial and interference of the global heart movement and can estimate exactly regional myocardium function. Previously reseaches in and out about the longitudinal systolic and diastolic function of the left ventricular in KD by velocity vector imaging is rarely.Objectives:To investigate the regional longitudinal systolic and diastolic function of left ventricular in KD patients with or without coronary artery dilatation by velocity vector imaging, to explore the relationship between coronary artery expansion or not and left ventricular regional function. Comparative study of left ventricular segmental myocardial systolic and diastolic function of KD in children between acute and convalescent stage, and compared with normal children, to observe the chang characteristics of left ventricular function.Subjects and method:we examined respectively 48 acute stage pationts (CAD group:n=28;CADN group:n=20),40 convalescence stage pationts and 30 normal children.They were matched with for sex,age. Exclusion criteria for all subjects were cardiovascular history, other febrile disease, severe cardiac arrhythmia and hyperthyroidism, anemia, kidney diseases et al that affect cardiac function in chilren.Dynamic imaging of apical long axis and four-chambe two-chamber view were obtained in all subjects, then the longitudinal systolic and diatolic period parameters were measured in all subjects respectively,such as:systolic max velocity(SVmax),systolic max strain (SSmax),systolic max strain rate(SSRmax),diastolic max velocity(EVmax), diastolic max strain rate(SRmax). The parameters were analysed between these groups.Results:Most of the Vmax,Smax and SRmax were significantly lower in CAD and CADN than the control group:Vmax,Smax and SRmax were significantly lower in CAD in all segment except anteroseptum middle and posterior basal segment (P<0.05). Lateral and septum Vmax,Smax and SRmax were significantly lower in CADN (P<0.05), SSmax,SSRmax in anterior and DSVmax,DS SRmax in basal,middle segmengt of anterior apical segment of inferior were significantly lower in CADN (P<0.05). meanwhile,CAD were much lower than CADN, especially in anterior basal,apical segment,inferior segmental (P<0.05).The Vmax,Smax and SRmax were significantly larger in recovery group than acute group, eapecially in basal and middle segment of septum(P<0.05), some segment such as lateral,anterior,inferior,systolic and diastolic Vmax,Smax and SRmax also were significantly larger in recovery group than acute group but not consistently(P<0.05),in the same time, some segments in lateral,septum,anterior and apical inferior,the Vmax,Smax and SRmax still significantly lower in recover group than control group.(p<0.05).The peak velocity of left ventricular long axis in the basal, middle,apical segment decreased progressively in Children, and peak strain and strain rate keep pace.Conclusion:The regional contraction and relaxation were obvious decrease in most segment in CAD and CAND than normal group, but the CAD decrease more significantly. Compared with the acute group, the left ventricular systolic and diastolic function of convalescence group has improved, but did not complete recovery. VVI can discover the small changes of the long axis of myocardial function objectively and accurately in patients with Kawasaki disease,and provides a new non-invasive and reliable method to assess left ventricular function。...