Characteristics of clinical signs, laboratory and instrumental examinations in various mechanisms of development of type 2 myocardial infarction

Aim. To identify different pathogenetic variants of myocardial infarction type 2 (MI-2).

Material and methods. Reviewed 4168 cases of MI admitted in multidisciplinary hospital for 10 years. 353 patients met the criteria for MI-2 without signs of coronary atherothrombosis (CA). In the study group, the features of clinical and laboratory-instrumental manifestations were evaluated.

Results. Cases of IM-2 were subdivided into 4 clinical-pathogenic variants (CPV): 1-CPV developed due an increasing in myocardial oxygen demand; 2-CPV, arising from a decrease in the supply of oxygen; 3-CPV associated with local coronary circulation disorder; 4-CPV developed due to the combined oxygen-energy imbalance. In 72 (20.4%) cases, 1-CPV was detected, caused by a hypertensive crisis and/or tachyarrhythmias; 2-CPV observed in 73 (20.68%) patients with hypotension, anemia, microvascular dysfunction, respiratory failure; 3-CPV caused by spasm and embolism of CA was detected in 47 (13.31%) cases; in 161 (45.61%) patients, IM-2 is associated with increased myocardial oxygen demand with reduced oxygen delivery. The gender and risk factors in groups are comparable. The average age of 1-CPV- and 3-CPV-patients was less and amounted to 65.7 and 56.5 versus 70.2 and 73.8 years in the 2-CPV and 4-CPV. Typical clinical and laboratory-instrumental signs of MI were common for patients with 1-CPV and 3-CPV, while 2-CPV and 4-CPV more often had chronic severe pathology, multivessel coronary disorder, and the clinical presentation and ischemic signs were less common.

Conclusion. Clinical manifestations and results of examination of patients with MI-2 depend on the mechanism of its development.