During a heart attack, also known as myocardial infarction or heartbeat, a part of the heart muscle (myocardium) is undersupplied due to a circulatory disorder (ischemia). This lack of oxygen causes this part of the heart muscle cells to die. The circulatory disorder occurs because one of the vessels supplying the heart muscle is blocked.
Therefore, the blood can no longer flow to the cells. Myocardial infarction is almost always caused by calcification of the vessels (arteriosclerosis). The arteries are responsible for supplying the body with oxygen-rich blood.
The arteries of the heart are called coronary arteries, and if they are calcified, it is called coronary heart disease (CHD). This is caused by harmful influences on the inner wall of the vessels (endothelium). This damage to the vessel wall leads to chronic inflammation.
Fatty substances (LDL cholesterol) can now be deposited in the previously damaged inner wall of the vessels. These cause an increasingly progressive inflammation of the vessel wall. Inflammatory cells, so-called macrophages, migrate through the blood into the innermost layer of the vessel wall.
These cells take up LDL cholesterol (LDL cholesterol is a transport form of cholesterol that is produced in increased amounts in foods that are too rich in fat) and try to break it down. However, this does not succeed completely, because of the oversupply of LDL the phagocytes are supersaturated after a certain time. Then they change into so-called foam cells.
These perish at the Cholesterin. The foam cells remain inder Gefäßwand and place a large portion of the Plaques. The inflammation causes scarring and fatty and calciferous plaques.
These reduce the diameter of the vessel. However, the main danger of plaques is that they can tear at any time. This is the most common cause of a heart attack.
The plaques are normally surrounded by a solid shell, tears this shell, and blood platelets (thrombocytes) immediately attach themselves to the tear to close it. However, since the diameter of the vessel is very reduced, complete closure may occur. As a result, the blood supply is interrupted and a heart attack occurs.
The heart muscle cells begin to die after 15-30 minutes without oxygen supply. Why some plaques rupture and others remain stable is difficult to say. A high number of fatty parts and little calcium should increase the risk of tearing.
Chronic inflammatory stimuli, such as smoking, also increase the probability of plaque tearing. Certain habits and factors increase the probability of calcification of the vessels in general and the coronary arteries in particular. This arteriosclerosis also increases the risk of getting a heart attack.
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