A new concept was adopted by the Fourth Universal Definition of MI Expert Consensus Document in 2018 – periprocedural myocardial injury after cardiac- and noncardiac interventions, which is distinct from myocardial infarction.It is difficult to diagnose a heart attack and myocardial damage after noncardiac surgery.Postoperative myocardial injury increases mortality and worsens the long-term prognosis and quality of treatment.The quality of surgical care is determined by surgical techniques and the course of the postoperative period. Although complications often negate the results of brilliantly performed surgery, many of them would happen irrespective of surgeon`s actions. The development of complications determining the outcome of treatment can be associated with cardiac pathology. Cardiac complications may develop due to existing comorbidities, hemodynamic instability during surgery, cardiotoxic effect of drugs, etc. In 40% of cases, the risk of cardiac death after noncardiac surgery is associated with the development of perioperative myocardial infarction or myocardial injury. Myocardial infarction is the most demonstrative complication, although it is difficult to diagnose in the perioperative period in case of asymptomatic course. The link between postoperative myocardial infarction and lethality is beyond doubt. Adopted in 2018, the Fourth Universal Definition of MI Expert Consensus Document introduced a new concept of periprocedural myocardial injury after cardiac- and noncardiac interventions, which are distinct from myocardial infarction. Myocardial injury requires laboratory tests to be diagnosed. However, myocardial injury itself affects postoperative mortality and significantly worsens the long-term prognosis and quality of treatment. This article reports the features of the etiopathogenetic mechanisms of cardiac complications during surgical care, as well as the multifactorial genesis of myocardial injury. The analysis of modern scientific literature on the diagnosis of myocardial damage is given. The need for early diagnosis of myocardial damage to create optimal management tactics for patients undergoing noncardiac interventions is demonstrated.