Abstract: Objective To explore the protective effect of L-carnitine on neonates with myocardial injury caused by as⁃ phyxia. Methods Forty-four neonates with myocardial injury caused by asphyxia were randomly divided into L-carnitine treatment group (21 cases) and control group (23 cases). Patients in control group were received routine treatment and pa⁃ tients in treatment group were given L-carnitine 0. 1 g/(kg·d) on the basis of routine treatment for 7 days. Symptoms and physical signs were observed before therapy and during the treatment in two groups. Before and after the treatment, plasma levels of free L-carnitine and cardiac troponin I (cTnI) were detected with the method of colorimetric assay and chemilumi⁃ nescent, respectively. Results The clinical effective rate was significantly higher in treatment group than that of control group (90.48% vs 60.87%, P < 0. 05). Compared with the control group, there was a significantly higher plasma concentra⁃ tion of free L-carnitine in treatment group after treatment [(27.00±5.69) μmol/L vs (13.20±3.04) μmol/L, P < 0.05]. In treat⁃ ment group, plasma concentration of free L- carnitine was significantly higher after treatment than that of pre- therapy [(14.87±3.95) μmol/L， P < 0.05]. Compared with the control group, there was a significantly lower plasma concentration of cTnI after treatment in treatment group [(0.025±0.006) μg/L vs (0.046±0.010) μg/L, P < 0.05]. In the treatment group, there was a significant correlation between decreased plasma concentration of cTnI and increased plasma concentration of free L- carnitine (r=0.899, P < 0.05). Conclusion Administration of L-carnitine can effectively decrease the abnormal plasma lev⁃ el of cTnI in neonates with myocardial injury caused by asphyxia, and thereby protect the myocardium.

Key words: asphyxia neonatorum, troponin I, L- carnitine, treatment outcome, drug evaluation