Echocardiographic examination on Vivid E9 (General Electric) echocardiographic device will be performed 5 ± 2 days after STEMI and repeated after 50 ± 10 days. Standard echocardiographic methods of M-mode, 2D, color, pulse, continuous doppler, tissue doppler and 2D speckle tracking will be used. The analysis will include the parameters of systolic and diastolic functions and myocardial mechanics in accordance with the latest recommendations of the European / American Echocardiographic Association.