Effect of magnesium on myocardial ischaemia and reperfusion injury

This study examined the effect of intravenous magnesium on the reperfusion injury of the porcine myocardium. Animals received general anaesthesia and the left anterior descending coronary artery was occluded for 15 minutes. Thereafter, reperfusion was allowed for 60 minutes. Regional ventricular function was measured with microsonometers. Animals were randomly assigned to a control (N = 6) or a magnesium group (N = 6). The latter received 30 mg/kg magnesium immediately before the release of the occlusion on the left anterior descending (LAD) artery. Results indicate that magnesium administration is associated with fewer ventricular arrhythmias and a rapid recovery (within 5 minutes) of myocardium systolic function once reperfusion was initiated. In the control group myocardial stunning was prolonged and more reperfusion arrhythmias occurred. However, in the group that received magnesium there was more diastolic dysfunction during reperfusion.