Changes in Myocardial Biomechanics and Early Short-term Doxycycline Therapy in Patients With Primary Anterior STEMI

Inclusion Criteria: * age ≥ 18 and ≤ 75 years at time of randomization (18 years and older) * ST-elevation Q wave myocardial infarction * term admission to an intensive care unit (ICU) in the first 24 hours of onset * the reperfusion of the infarct-related coronary artery is not later than 24 hours after the initial onset of acute transmural myocardial infarction * written the informed consent to participate in research Exclusion Criteria: * atrial fibrillation, a permanent form * valvular heart disease * severe comorbidity * acute heart failure according to the Killip classification IV FC (functional class) * history of chronic heart failure (NYHA III-IV) * poor image quality for Echocardiography * sinus bradycardia - heart rate of under 50 beats per minute, interventricular conduction delay (QRS \> 0,11 s.) and atrioventricular block II-III degree