Benzer W
Abteilung für Innere Medizin (Kardiologie), Landeskrankenhaus Feldkirch, Osterreich.
Wien Klin Wochenschr. 1997;109 Suppl 2:38-41.
Magnesium is an essential element for the regulation of energy dependent metabolism and transmembranous electrolyte flow. Despite the present controversial interest, magnesium has some beneficial effects on several manifestations of coronary artery disease and myocardial infarction. In supraphysiologic serum levels magnesium causes dilatation of epicardial coronary arteries and modulates better diastolic relaxation of the left ventricle. It protects the ischaemic myocardium against calcium overload, preserves the intracellular ATP and brakes the acidosis caused by anaerobic metabolism and free radicals with subsequent cell necrosis. Spontaneous depolarization of the myocardial cell decreases after magnesium administration. Supraventricular and ventricular arrhythmias become less frequent under supraphysiologic magnesium serum levels. Also magnesium inhibits platelet aggregation. The conflicting results of randomized trials examining the efficacy of magnesium supplementation have failed to establish conclusively whether magnesium is generally useful in coronary artery disease and after myocardial infarction. Although findings of experimental studies showed beneficial effects of supraphysiologic administration of magnesium before or in the early phase of ischaemia and reperfusion during acute myocardial infarction. By the way supraphysiologic magnesium application is safe, cheap and has no side effects in common dosage.
镁是调节能量依赖性代谢和跨膜电解质流动的必需元素。尽管目前存在争议，但镁对冠状动脉疾病和心肌梗死的几种表现具有一些有益作用。在超生理血清水平时，镁可引起心外膜冠状动脉扩张，并更好地调节左心室舒张期松弛。它可保护缺血心肌免受钙超载影响，维持细胞内三磷酸腺苷（ATP）水平，并抑制无氧代谢和自由基引起的酸中毒及随后的细胞坏死。给予镁后心肌细胞的自发去极化减少。在超生理镁血清水平下，室上性和室性心律失常的发生频率降低。此外，镁还可抑制血小板聚集。评估补充镁疗效的随机试验结果相互矛盾，未能最终确定镁在冠状动脉疾病和心肌梗死后是否普遍有用。尽管实验研究结果表明，在急性心肌梗死缺血和再灌注之前或早期给予超生理剂量的镁具有有益作用。顺便说一下，超生理剂量的镁应用安全、便宜，且常用剂量无副作用。
