Study of Microvascular Dysfunction, CFR and Cardioprotective Effect of Early Administration of Esmolol in MI

"the loading dose of 500 mkg/kg for 1 minute, followed by the initial rate of 50 mkg/kg/min. Individual titration depending on the desired hemodynamical effect (to the heart rate of 60 bpm or to the maximum tolerated dose maintaining stable hemodynamics) every 5-15 minutes (the maximum allowed rate of administration is 300 mkg/kg/min) for 6 hours.~Thereafter patients in both treatment arms - the IV esmolol arm and the placebo arm, will be administered oral β-adrenergic blockers, if decided so by the treating physician and unless contraindicated."