[Significance of supraphysiologic administration of magnesium after myocardial infarct]

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.