Medical Encyclopaedia › Heart attack (short definition)
In brief: In a heart attack (myocardial infarction), a coronary artery is suddenly blocked, so that part of the heart muscle no longer receives blood and begins to die. It is a life-threatening emergency in which the emergency number (112 in Europe) must be called immediately.
How does a heart attack occur?
It is usually based on coronary heart disease: over years, deposits (plaques) of fat, inflammatory cells and calcium form in the coronary arteries. If such a plaque ruptures, a blood clot forms at that point, completely or partially blocking the vessel. Doctors distinguish between ST-elevation myocardial infarction (STEMI) with typical ECG changes and non-ST-elevation myocardial infarction (NSTEMI); both are grouped under the term acute coronary syndrome.
Signs
Typical signs are severe pain, pressure or tightness behind the breastbone lasting longer than five minutes, which can radiate to the arms, neck, jaw, back or upper abdomen. Shortness of breath, cold sweat, nausea, pallor and fear of dying are often added. Women, older people and people with diabetes in particular often have less clear-cut symptoms such as shortness of breath, nausea, upper abdominal pain or unusual exhaustion – as a result, help is often called too late.
What to do in an emergency?
Call the emergency number immediately; do not drive to hospital yourself. The person affected should rest with the upper body raised, tight clothing should be loosened and they should not be left alone. In the case of unconsciousness without normal breathing, start chest compressions immediately and, if available, use a defibrillator (AED).
Treatment
The aim is to reopen the blocked vessel as quickly as possible. The standard is cardiac catheterisation, in which the narrowing is widened with a balloon and usually kept open with a stent (percutaneous coronary intervention). If a catheter laboratory cannot be reached in time, the clot can be dissolved with medication. Afterwards, patients usually receive long-term medication: antiplatelet agents (usually two at first), a statin to lower LDL cholesterol and, depending on the situation, beta-blockers and ACE inhibitors. Bypass surgery is rarely necessary.
After the heart attack and prevention
Cardiac rehabilitation helps patients regain their fitness and provides knowledge about medicines, exercise and diet. To prevent a first or further heart attack, stopping smoking, treating high blood pressure, diabetes and raised LDL cholesterol, regular exercise, a healthy body weight and a balanced diet are crucial.
Related terms in the encyclopaedia
Acute coronary syndrome, Coronary heart disease (CHD), Angina pectoris, Cardiac catheter, Stent, Troponin, Resuscitation, Statins, LDL cholesterol, Cardiac rehabilitation
Further reading on Medizin Aktuell
- Gene editing against heart attack: one infusion lowers LDL cholesterol
- Lowering cholesterol with gene scissors: CRISPR therapy CTX310
Sources
- European Society of Cardiology (ESC): 2023 ESC Guidelines for the management of acute coronary syndromes, European Heart Journal 2023
- Bundesärztekammer, KBV, AWMF: Nationale VersorgungsLeitlinie Chronische KHK
- Deutsche Herzstiftung: Patienteninformationen zum Herzinfarkt
Note: This article is for general information and does not replace advice, diagnosis or treatment from a doctor or pharmacist. Last updated: October 2026.