Myocardial protection related to magnesium content of cold blood hyperkalemic cardioplegic solutions in CABG.
The objective of this study was to investigate whether the addition of magnesium to a hyperkalemic cardioplegic solution containing 1.2-1.5 mmol/L ionized calcium improves myocardial protection. Twenty-seven coronary artery disease (CAD) patients underwent coronary artery bypass grafting (CABG) received hyperkalemic (20-22 mmol/L potassium) cardioplegic solutions containing 1.2-1.5 mmol/L ionized calcium and were randomized to one of the following groups: Group A (n = 9) received 3-4 mmol/L magnesium cool blood cardioplegia (4 degrees C), Group B (n = 9) received 8-10 mmol/L magnesium cold blood cardioplegia (4 degrees C). Group C (n = 9) received 16-18 mmol/L magnesium cold blood cardioplegia (4 degrees C). The effect of myocardium protection of the three kinds of cardioplegic solutions were evaluated by clinical outcome, cTnI and CK-MB mass. Serial venous blood samples were obtained before induction, after cardiopulmonary bypass (CPB), postoperative 6 h, 24 h, 72 h, and 6th day, respectively. The percentage of myocardial autoresusciation in group B (100%) was significantly higher than that in groups A (77.8%) and C (66.7%). One patient in group A and two patients in group C needed an interim pacemaker, but none in group B. The period of postoperative mechanical ventilation and ICU stay in group B was shorter than in the other two groups. The level of cTnI and CK-Mb mass increased from postoperative 6 h (p < .05), reached peak in 24 h-72 h, and recovered postoperative 6th day. As compared with groups A and C, the plasma concentrations of cTnI and CK-MB mass in group B were significantly lower at 6 h, 24 h, and 72 h (p < .01). 8 approximately 10 mmol/L magnesium cold blood cardioplegia provides better myocardium protection than higher or lower concentrations.
Ji
Bingyang
B
Department of Cardiopulmonary Bypass, Cardiovascular Institute and FuWai Hospital, CAMS and PUMC, Beijing, People's Republic of China. bingyang-j@hotmail.com
Feng
Zhengyi
Z
Liu
Jinping
J
Long
Cun
C
D001639:Bicarbonates; D001769:Blood; D002122:Calcium Chloride; D002314:Cardioplegic Solutions / Q000008:administration & dosage / Q000378:metabolism*; D002681:China; D003080:Cold Temperature; D001026:Coronary Artery Bypass / Q000379:methods*; D003402:Creatine Kinase / Q000097:blood; D052279:Creatine Kinase, MB Form; D006801:Humans; D007036:Hypothermia, Induced; D007527:Isoenzymes / Q000097:blood; D008274:Magnesium / Q000008:administration & dosage / Q000378:metabolism*; D017202:Myocardial Ischemia / Q000517:prevention & control*; D011188:Potassium / Q000008:administration & dosage / Q000378:metabolism*; D011189:Potassium Chloride; D011446:Prospective Studies; D012107:Research Design; D012965:Sodium Chloride; D019210:Troponin I / Q000097:blood
D001639:Bicarbonates; D002314:Cardioplegic Solutions; D007527:Isoenzymes; C041711:St. Thomas' Hospital cardioplegic solution; D019210:Troponin I; D012965:Sodium Chloride; D011189:Potassium Chloride; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form; D008274:Magnesium; D002122:Calcium Chloride; D011188:Potassium