Studies On Correlation Among Different Degrees Of Hypoxia,Changes In Serum Cardiac Enzyme Activities On Preoperative Patients With Tetralogy Of Fallot And Their Early Prognosis After Primary Repair

Objective:To investigate the correlation among different degrees of hypoxia, changes in serum cardiac enzyme activities on preoperative patients with tetralogy of Fallot (TOF) and early prognosis after primary repair of TOF indicated by intensive care unit (ICU) stay time, prolonged inotropic support time, ventilation support time and presence of concurrent events.Methods: Between July 2006 and September 2007, 75 consecutive typical TOF patients underwent primary repair of TOF. Their age ranged from 8 months to 15 years (2.82±2.68 years). 103 healthy children in medical examination in out-patient clinic during that period were included in control group. The serum creatine kinase isoenzyme (CK-MB) , creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) activities in both groups were measured and compared by t test. The correlation between preoperative percutaneous blood oxygen saturation (SPO₂) of patients with TOF and serum CK-MB, CK, LDH and AST activities were analyzed separately. Prolonged inotropic support time, ventilation support time and ICU stay time after primary repair of TOF were recorded and their correlation with preoperative SPO₂ and serum cardiac enzyme activities were analyzed separately. TOF patients were seperated into two groups according to presence of concurrent events. Preoperative SPO₂ and serum CK-MB, CK, LDH and AST activities were compared between the two groups.Results: The differences in serum CK-MB, LDH and AST activities between TOF group and control group were highly statistically significant (P<0.01) . There were no correlation between preoperative SPO₂ and serum CK-MB, CK, and AST activities but negative correlation between SPO₂ and serum LDH activities (r=-0.272,P=0.018) .Preoperative SPO₂ and prolonged inotropic support time, ventilation support time, ICU stay time presented obiviously negative correlation separately. There were positive correlation between serum CK-MB, LDH activities and prolonged inotropic support time, ventilation support time, ICU stay time. Serum CK activities only presented positive correlation with ventilation support time and ICU stay time,while there were positive correlation between serum AST activities and prolonged inotropic support time, ICU stay time. No stastical significances were found in preoperative SPO₂, serum CK-MB, CK, LDH and AST activities between the two groups with or without concurrent events.Conclusions: Different degrees of myocardial injury were found in TOF patients in our study. The more serious injury the myocardium in TOF suffered, the longer early postoperative course patients would have. Preoperative chronic hypoxia is one factor influencing normal cardiac function in TOF. The lower preoperative SPO₂ TOF patients got, the worse outcome they had. Different organ disorders were included in the postoperative concurrent events, of which serum cardiac enzyme activities were not the main influencing factor. So there was no relationship between the two groups.