Text Box: USE OF CARDIAC TROPONIN I PEDIATRICS DISEASE Xing SH, Lin SX, Fan CJ, Pan YH, Chen ZH, Liu W Children's Hospital, Tianjin, China Objective: To establish normal values and determine the impact of acute myocardial injury on serum cardiac troponin I (cTnI). Methods: Serum MB isoenzyme of creatine kinase (CK-MB), cTnI, was detected in all cases (n=230). Cardiac troponin T (cTnT) was detected in part cases. (n=153). All patients underwent 12 -lead electrocardiography, X-ray, two-dimensional echocardiograms. Concentrations of cTnI were measured in six groups of children. Group A represented ambulatory padiatric patients with no cardiac disease. (n=70, 31 boys, 39 girls, mean age 104 months, range 2 to 196 months). Group B represented patients with acutemyocarditis. Group C was composed of patients with supraventricular tachycardia (SVT) (n=16) and extrasystole. (n=50) Group D and group E were composed of patients with congenital heart disease (n=19) and Kawasaki disease (n=22) respectively. Group F was composed of severe acute illness with no cardiac disease. (n=30) Results: The cTnI concentrations were generaly 0.143¡À101ug/L P95=0.29ug/L and the cTnT concentrations were generaly 0.06¡À0.05ug/L P95=0.14ug/L in the group A. There was statistical difference between level of CK-MB and cTnI in the group A. (X2=5.123 P¡´0.05). There was no statistical different between level of CK-MB and cTnT in the group A. The level of cTnI were apparent higher than CK-MB in the group B. The CK-MB concentrations were higher than cTnI and cTnT. (P=0.00089 P=0.00008 respectively) in the Group F. Conclusion: Sensitively and specificity of cTnI is better marker For the diagnosis of acute myocardial injury than CK-MB and cTnT.The serum cTnI can be used as importance marker for dignosising acute myocarditis. The serum cTnI level could be a useful new biologic for the early diagnosis of acute myocarditis in Kawasaki disease. 2310