Objective:To evaluate the effects of beating-heart and arrested heart intracardiac procedure on the expression of tumor necrosis factor alpha (TNF-α) mRNA in myocardium.Methods: Thirty congenital ventricular septal defect (VSD) patients aged from 5 to 10 years old were randomly divided into 2 groups equally. Group A underwent traditional arrested-heart intracardiac procedures; group B underwent beating-heart procedures. Specimens of myocardium were obtained at the onset (baseline) and the end of cardiopulmonary bypass (CPB) for the determination of TNF-α mRNA. Concentration of TNF-α was respectively measured after anesthetic induction (T1), 20 min after the beginning of CPB (T2), at the end of CPB (T3) and 6, 12, 24 h after CPB (T4-6) in all patients. After separating polymorphonuclear leucocyte (PMN), we distilled nuclear protein and mensurated the activation of nuclear factor-κB (NF-κB) by electrophoretic mobility shift assay (EMSA). Results:Compared with baseline, the expression of TNF-α mRNA significantly increased in both groups (P<0.05). TNF-α mRNA level of group A was significantly higher than that of group B at the end of CPB (P<0.05). The plasma concentration of TNF-α and neutrophil NF-κB activity in group A was significantly higher than that of group B at T4-6 (P<0.05). Conclusion:Compared with traditional arrested CPB, beating heart intracadiac procedure can effectively reduce the expression and release of TNF-α; it will benefit the protection of pediatric myocardial during CPB.