With a heart attack (myocardial infarction) almost everyone has already come into contact. Be it as a sufferer or as an acquaintance of someone affected by a heart attack. If our circulatory motor lacks oxygen, it starts to stutter or stops completely. This does not happen so rarely: More than 220,000 people suffer a heart attack in Germany every year, and about 50,000 cases are fatal.
Heart attack due to reduced oxygen supply
The heart muscle, like any other organ, requires oxygen for its activity. This is provided by the blood in the coronary vessels. If these are narrowed, the muscle can no longer pump sufficiently – which leads to limited exercise capacity and heart pain (angina pectoris).
The heart attack is, so to speak, the maximum manifestation of the reduced oxygen supply: At one point, the blood supply is suddenly interrupted to such an extent that the muscle supplied by it (myocardium) is not only restricted in its work, but itself receives too little oxygen and nutrients and dies – a heart attack, often with partly life-threatening consequences.
If the affected person survives the heart attack, the infarct tissue scars over and remains functionless.
Forms of heart attacks
Depending on which of the halves of the heart is affected by a heart attack, a distinction is made between left heart infarction and right heart infarction. Depending on the area affected in a heart attack, there are further anterior and posterior wall infarctions. The right ventricle is rarely affected and then usually together with the left ventricle in an infarction, which is related to the course of the three main coronary arteries.
If necrosis (“death”) affects all tissue layers in a myocardial infarction, it is called a transmural infarction; if only the inner layer is damaged, it is called a stratified infarction.
Harbingers of a heart attack
In the past, prolonged attacks of angina pectoris (decrescendo angina) were considered a harbinger of a heart attack. In the meantime, it is known that heart muscle can also be destroyed during these attacks. This is why this form is now also classified as an infarction.
In contrast to the classic infarction, however, the typical changes in the ECG do not appear here – the elevation of the ST segment is therefore missing. For this reason, this form of infarction is also called NSTEMI (non-ST-segment elevation myocardial infarction), whereas the classic infarction is called STEMI (ST-segment elevation myocardial infarction). The generic term for both forms is acute coronary syndrome.
