Aim To study the effects of inhibition of NF-κB in the early phase after myocardial ischemia on myocardial reparation in rats.Methods The myocardial ischemic injury models were established by hypodermic injection of high dose of ISO in rats.Surviving rats were randomly divided into experimental group and treated group,meanwhile control group was set.Then treated group was injected PDTC 100 mg/(kg·d)for 26 days.Myocardial pathomorphologic changes,NF-κBp65 activation,capillary density and myofibroblast accumulation were investigated.Then cardiac structure and function were assessed by echocardiography on day 14 and 28 of experiment.Results Cardiac necrotic areas were similar between experimental group and treated group.PDTC inhibited the activation of myocardial NF-κB,delayed the replacement of the damaged myocardium with granulation tissue,significantly depressed capillary density in the border area of necrosis and decreased myofibroblast accumulation in the zone of necrosis.The ratio of ventricular aneurysm formation in treated group was higher than experimental group.On day 28,the left ventricular functions in treated group were worse than that in experimental group.Conclusion Inhibition of NF-κB in the early phase after experimental myocardial ischemic injury in rats may be adverse to myocardial reparation,and may aggravate heart failure.