Validity Study of Glutamine to Improve Cardiac Function in Cardiac Surgery

In view of the lack of large-scale clinical study and potent evidence-based medicine, the investigators designed a randomized, double-blind, placebo-controlled study to ascertain whether preoperative intravenous administration with glutamine can improve the postoperative cardiac function and prognosis of adult patients undergoing cardiac surgery. The investigators want to detect the levels of myocardial protein O-GlcNAc modification and HSP70 expression, changes in sensitive indicators of myocardial injury, systemic inflammatory reaction and oxidative stress levels, and to examine the correlation between these changes and Clinical manifestations. The ultimate goal of the study is to explore a new way for clinical myocardial protection.