The Left Ventricular Systolic Function Of Kawasaki Disease Evaluated By Two-dimensional Speckle Tracking Echocardiography In Base And Exercise Stress Test

Objective:Kawasaki disease(KD)is an acute vascular inflammation of unknown etiology.The lesions mainly affect the small and medium arteries of the whole body.Among them,coronary artery injury is the most common and serious complication.KD has become the first cause of acquired heart disease in children..Myocardial dysfunction caused by KD coronary artery disease is a sequela of the main complications of KD.The main way to assess myocardial dysfunction is the assessment of left ventricular systolic function,but conventional transthoracic echocardiography has limited detection of KD subclinical systolic dysfunction.With the development of technology,two-dimensional speckle tracking echocardiography(2D-STE)has become a new technique for the evaluation of left ventricular regional and global systolic function.The left ventricular global longitudinal strain(LVGLS)is recommended and reliable for many studies.The method,LVGLS,is of great value in detecting local myocardial dysfunction in coronary artery disease.On the other hand,cardiac ultrasound exercise stress testing can increase the assessment of subclinical myocardial dysfunction.At present,the research on 2D-STE technology mostly focuses on the acute phase of KD,but the damage of KD to cardiac function is continuous.It is found that the coronary artery lesions tend to be stable after 6 months of KD diagnosis,so the state of this phase would give clinicians more information.Injury to systolic function plays an important role in the late follow-up and early intervention of KD individuals.Our goal is to study the left ventricular local and global systolic function of patients with coronary artery stability after KD by 2-STE technique,to evaluate the advantages of this technique in comparison with conventional echocardiography,and finally to apply the valuable information of subclinical change assessment.Methods:A case group(KD group)enrolled at the first affiliated hospital of Kunming Medical University from December 2017 to December 2018,with a KD diagnosis for more than 6 months.38 patients were divided into different subgroups according to different coronary artery conditions.Group A was with coronary artery aneurysm(thrombosis or not).Group B was with mild to moderate dilatation of coronary artery,and group C was with normal coronary artery diameter.50 normal age-matched children were enrolled as control group.Two-dimensional echocardiography was used to detect the usual indexs including the LV ejection fraction.And 2D-STE was used to obtain the local strain and GLS at rest and exercise status.Furthermore,the high risk factors related to CALs in KD group were analyzed.1.Comparative analysis:Strain of left ventricular basal segment,middle segment,apical segment and LVGLS in KD subgroups and control group before and after exercise were analyzed.2.Correlation analysis:Laboratory indicators related to acute phase of KD in each subgroup were applied to Logistic regression analysis to see whether it is an influencing factor of LVGLS changes.Results:Firstly,there was no statistical difference of the general clinical data between KD subgroups and control group,including the LV ejection fration.Secondly,at rest,the value of left ventricular basal sengment and LVGLS decreased significantly in KD subgroups compared with control group and also significant within subgroups(P<0.05).The middle and apical segment strain were different apparently between group A and B,group A and C(P<0.05).In addition,the more severe the coronary lesions in KD patients were,the lower the GLS would be(P<0.05).At exercise,the basal segment strain and LVGLS still took significant differences between 3 subgroups and the control group(P<0.001).The left ventricular local and global strain of the control group increased significantly after exercise(P<0.05).In the case group,the local strain and LVGLS were statistically different between group A and B and group A and C(P<0.001),but there was no statistical difference between group B and C(P>0.05).Thirdly,acute laboratory indicators,like PLT,hs-CRP,ALT,and AST in group A were significantly higher than those in group C(P<0.05),and hs-CRP and ESR in group A were higher than those in group B(P<0.05).There was significant difference in ESR between group B and group C(P<0.05).Multiple linear regression analysis of the measured data including WBC,PLT,hs-CRP,ESR,ALT,AST,Alb,and Hb showed that the PLT had an effect on the late LVGLS.The regression model was:LVGLS=-(19.66-0.37PLT)%.Conclusions:1.KD Patients with normal left ventricular systolic function after 6 months of diagnosis by conventional echocardiography would be combined with different degree injury of left ventricular local and global systolic function by 2D-STE assessment.The more severe the coronary lesions in KD patients were,the lower the LVGLS would be.2.After exercise test,there were decreased values in the left ventricular local and overall strain in CAA group,while the other subgroups and control group had increased strain values.So KD with CAA might have diffuse vascular stenosis inducing myocardial ischemia.3.The increase of PLT in acute phase had a negative effect on the LVGLS.