Study On The Application Of Ultrasound-based AFI Of Left Ventricular Myocardium Mechanicsin The Diagnosis Of Viral Myocarditis

Objective:To investigate the diagnostic value of automatic mechanical imaging(AFI)technique based on two-dimensional speckle tracking imaging to evaluate the mechanical properties of left ventricular myocardium in patients with viral myocarditis.Methods:The subjects of the study were 36 patients with clinically diagnosed mild viral myocarditis(case group)and 32 normal health subjects as control subjects.On the basis of routine echocardiographic examination,the automatic ultrasonic function with two-dimensional spot tracking was used.Automated functional imaging(AFI)technique,obtaining systolic left ventricular long-axis strain and bull’s eye pattern of all subjects,measuring long-axis systolic peak strain(RLPS)and left ventricular overall long axis in each segment of the left ventricular wall.Peak systolic strain(GLPS),left ventricular end-diastolic diameter(LVEDD),ejection fraction(LVEF),stroke volume(SV),cardiac output(CO),and cardiac index(CI)values were recorded and calculated.In addition,serum allergen cardiac troponin I(hs-CTnI)and creatine kinase isoenzyme(CK-MB)levels were measured in all subjects.Results:1,compared with the control group,in myocarditis group,RLPS of left ventricular wall,left ventricular total systolic strain(GLPS)were significantly reduced,while hs-CTnI level were significantly higher(P<0.05),there was no significant difference in LVEDD,LVEF,SV,CO,CI values and,CK-MB level between the two groups(P>0.05)2.Correlation analysis showed that there was a significant correlation between GLPS and LVEF,SV and hs-CtnI(r=0.64;0.59;-0.73;P<0.01),but no significant correlation with LVEDD,CO,CI and,CK-MB(P>0.05).The ROC curve analysis showed that the absolute value of GLPS was less than 17.72%,and the sensitivity of hs-CtnI elevation was 95.81%,the specificity was 86.31%,and the area under the curve was 0.89.Conclusions:2D-STI-based left ventricular long-axis strain can accurately reflect he left ventricular myocardial mechanics changes in patients with mild viral myocarditis,API technology can provide a quick,simple and reliable new means for the early diagnosis of viral myocarditis.