The perioperative effect of magnesium sulfate in patients with concentric left ventricular hypertrophy undergoing cardiac surgery: A double-blinded randomized study

Objective: The objective of this study was to assess the cardioprotective effect of magnesium sulfate in patients with left ventricular concentric hypertrophy undergoing cardiac surgery. Design: The study was a double-blinded randomized study. Setting: This study was conducted at a cardiac center. Patients: The study included 250 patients. Intervention: The study included two groups (each = 125): Group M – the patients who received magnesium sulfate infusion (15 mg/kg/h). The infusion was started 20 min before induction, during surgery, and the first postoperative 24 h. Group C – the patients who received an equal amount of normal saline. Measurements: The variables included troponin I level, creatinine kinase-MB (CK-MB) level, electrocardiograph (ECG) with automatic ST-segment analysis (leads II and V), E/A peak ratio, end-diastolic volume, cardiac index (CI), heart rate, mean arterial blood pressure (MAP), mean arterial pulmonary pressure (mPAP), pulmonary and systemic vascular resistances, and pharmacological and mechanical support. Main Results: The troponin I level, CK-MB, and ECG changes were lower in Group M than Group C (P < 0.05). The E/A peak ratio and end-diastolic volume increased in Group M than Group C (P < 0.05). There was a significant increase in the CI and a decrease in the heart rate, mPAP, pulmonary vascular resistances, and pharmacological and mechanical support in Group M compared to Group C (P < 0.05). There were minimal changes in the MAP and systemic vascular resistance in Group M compared to Group C (P < 0.05). Conclusion: The magnesium sulfate provides a cardioprotective effect in patients with concentric ventricular hypertrophy undergoing cardiac surgery. It decreases the incidence of perioperative myocardial infarction and arrhythmia. Furthermore, it decreases the requirement of pharmacological and mechanical support.

Early Diagnosis of Myocardial Injury in Neonatal Asphyxia / 实用儿科临床杂志

Objective To investigate the clinical value of cardiac troponin Ⅰ(cTnⅠ) and creatinine kinase MB(CK-MB) in early diagnosis of myocardial injury(MCI) in neonatal asphyxia.Methods The serum cTnⅠ and CK-MB in neonates [34 with asphyxia and MCI,38 with asphyxia but no MCI(NMCI)],and 30 cases of normal control(NC) were measured with direct immunoassay chemiluminometric technology and immunoinhibition enzymes-activated assay.Results The cTnⅠ level in NC group had no changes within 10 days after birth,MCI group were significantly higher than those in NMCI and NC groups(all P0.05).The diagnostic sensitivity,specificity and accuracy of cTnⅠ for neonates with MCI were 91%,88% and 89%,respectively;and of CK-MB were 85%,68% and 74%,respectively.Conclusions cTnⅠ and CK-MB can be taken as early diagnostic markers of MCI in neonates with asphyxia,(cTnⅠ) is better than CK-MB.