EFFECTS OF INTRAVENOUS MAGNESIUM THERAPY ON ISCHEMIA REPERFUSION INJURY IN ACUTE MYOCARDIAL-INFARCTION/

The concept of reperfusion-induced injury has aroust special interest over the past decade since early restoration of coronary blood flow pl ays pivotal role in the treatment of patients with acute myocardial in farction. There is experimental evidence that oxygen-derived free radi cals, activation of the complement system, and adhesion molecules may account for the development of reperfusion injury. Reduction of reperf usion injury may be the mechanism underlying the beneficial effects of magnesium in acute myocardial ischemia. Numerous previous clinical tr ials on effects of intravenous magnesium in patients with acute myocar dial infarction provided encouraging results with respect to mortality benefit, infarct size reduction, and reduction of arrythmias. A recen tly published large-scale trial, ISIS-4, however, failed to show the c linical benefit of intravenous magnesium therapy, and caused major con troversies in this field. It is suspected that the late timing of magn esium therapy as was performed in ISIS-4 may be responsible for the ne gative results. Further clinical trials have now been initiated to cla rify the beneficial effects of magnesium in acute myocardial infarctio n, with a special remark on optimal timing and dose regimen of intrave nous magnesium therapy.