Оригінальні дослідженняdrug treatment in patients of the control group there was a significant clinical and functional improvement, though sinus tachycardia, ventricular extrasystole of high grades and supraventricular extrasystole remained resistant to treatment. There was also a pronounced endothelial vascular dysfunction, which in the process of standard treatment in patients of the control group did not reach the level of healthy individuals (p < 0.05).Conclusions. In patients with acute MI with comorbid MS, who underwent balloon angioplasty and stenting of the infarct-dependent coronary artery, a pronounced vascular endothelial dysfunction and electrical instability is observed, accompanied by reperfusion arrhythmias and arrhythmias. The use of arginine-carnitine mixture as upstream therapy helped to restore endothelial function and showed a pronounced antiarrhythmic effect, which significantly reduced the incidence and severity of complications of acute MI such as reperfusion arrhythmias.