Infarct

In general, an organ or tissue part where necrosis begins due to impaired arterial blood flow. There are various types of infarction: anemic (ischemic) – caused by complete circulation disturbance, hemorrhagic, and mixed. The most life-threatening is myocardial infarction. It occurs when there is a sudden lack of oxygen in the heart muscle because blood flow decreases or stops in a branch of the coronary artery. This happens when a coronary artery is narrowed by accumulated atherosclerotic plaques, mechanically compressed from the outside, or blocked by a thrombus, less commonly – an embolus. This leads to a significant decrease or complete cessation of blood supply to certain parts of the myocardium (depending on which and how large a coronary artery is blocked). If blood flow is not restored within 20-40 minutes, significant biochemical changes occur in the heart muscle cells. Myocardial infarction can occur when the heart muscle suddenly requires more oxygen after physical exertion or emotional stress. Myocardial infarction is also promoted by so-called risk factors: smoking, high blood pressure, diabetes mellitus, high cholesterol levels in the blood (dyslipidemia), constant emotional stress, frequent physical fatigue, obesity, a predisposition to cardiovascular diseases among family members.

Source | Glossary of Most Commonly Used Biomedical Terms and Concepts | Lithuanian University of Health Sciences | Academician Professor Antanas Praškevičius, Professor Laima Ivanovienė