ABSTRACT
ObjectiveTo investigate the effects of cardioplegic solution enriched with different doses of glutathione on myocardial injury in children undergoing cardiac surgery under cardiopulmonary bypass (CPB).MethodsForty-eight ASA [Ⅱ or Ⅲ patients aged 2-5 yr undergoing repair of ventricular septal defect under CPB were randomly divided into 4 groups (n ＝ 12 each):control group (group C) and cardioplegic solution containing 3 different-dose of glutathione groups ( group G1-3 ).Glutathione 50,75,100 mg/kg were added to cardioplegic solution in group G1-3 respectively.Blood samples were collected before operation (T0),at 30 min after release of aortic cross-clamp (T1),at 6,12,24 h after termination of CPB (T2-4) for determination of plasma cTnI concentration.Myocardial specimens were obtained from right auricle before aortic cross-clamp and 15 min after release of aortic cross-clamp.The ultrastructure of myocardium was examined with scanning electron microscope.A mitochondrial FlaMeng semiquantitative analysis was done.ResultsThe plasma concentration of cTnI at T3,4 were significantly lower in groups G1,2 than in group C.The plasma concentration of cTnI at T1-4 were significantly lower in group G3 than in group C and group G1,2.The quantization score of myocardial mitochondria at 15 min after release of aortic cross-clamp were significantly lower in group G3 than in group C and group G1,2.Micorscopic examination showed that the injury to myocardial ultrastructure was attenuated in group G3 compared with group C.Conclusion Cardioplegic solution enriched with glutathione can reduce myocardial injury induced by CPB in a dose dependent manner.Glutathione 100 mg/kg can exert a visibly protective effect on myocardium.