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.
Department of Cardiopulmonary Bypass, Cardiovascular Institute and FuWai Hospital, CAMS and PUMC, Beijing, People's Republic of China. bingyang-j@hotmail.com
Bingyang
B
Ji
Zhengyi
Z
Feng
Jinping
J
Liu
Cun
C
Long
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