Objective:To compare the myocardial toxicity and the influence of MLAC—ropivacaine and MLAC—bupivacaine on myocardial zymogram of parturients during the first stage of labor while using epidural block for pain relief

and to provide experimental bases for choosing reasonable local anesthetics for labor analgesia.Methods:20 parturients were chosen and divided into two groups randomly (one is bupivacaine group

the other ropivacaine group).Each parturient received 20ml of MlAC-anesthetics at the required time.Blood samples were obtained from 20 parturients at different intervals and blood serum from these samples were preserved at -70℃ to determine their AST

LDH

CK-MB

and also to evaluate the analgesic effect

monitor and manage these parturients and fetus after analgesia.Results:There were no significant difference in the following aspects:(1)general data (2) obstetric character (3) analgesic effect

vital signs (4) Apgar scores of neonates (5) partal pattern (6) bleeding volume (7) myocardial zymogram between groups at each time point.There were significant difference in myocardial zymogram at different time.Conclusion:The change in myocardial zymogram is correlated to birth process

but it has nothing to do with analgesic formula.Both MLAC-ropivacaine and MLAC-bupivacaine are safe and effecive for pain relief during the first stage of labor by epidural block.