Synonym
Medical: Myocardial infarction
Definition of heart attack
Myocardial infarction is defined as the death of heart muscle cells due to an oxygen deficiency (ischemia) of the heart or a circumscribed region of the heart. In technical jargon, this is also known as ischemic myocardial necrosis. The heart muscle cells are no longer (sufficiently) supplied with oxygen and nutrients, which is why they die (cell necrosis) and are converted into connective tissue cells that can no longer carry out any cardiac action.
This results in a scar on the heart. Most heart attacks occur at the base of coronary heart disease (CHD), which is mainly caused by a narrowing (atherosclerosis) of the coronary vessels (coronaries). In a healthy (physiological) state, the coronary vessels supply the heart muscle cells with oxygen and nutrients.
If these vessels are affected by atherosclerosis and are constricted or even blocked by deposits on the vessel walls, the cells receive an insufficient amount of oxygen and die. Among other things, this leads to great pain and a feeling of weakness in the patient. The World Health Organization (WHO) speaks of a heart attack if markers for unstable angina pectoris are present in the blood, which show damage to the heart muscle.
Angina pectoris means chest pain (“tightness in the chest”) due to a critical narrowing of the coronary arteries, which occurs at rest and whose duration, severity and frequency are increasing. The heart muscle proteins troponin I and troponin T have established themselves as sensitive markers of heart muscle damage: they are released when the cells enter the bloodstream and their increased concentration can be determined by taking a blood sample. Together with coronary heart disease, myocardial infarction is referred to as acute coronary syndrome because the symptoms of these two diseases are very similar and unstable angina pectoris is often followed by a heart attack. In addition, an ECG change and the angiographic findings are a sensitive marker of a heart attack. Therefore, a summarizing designation and a common diagnostic and therapeutic approach was found.
