Myocardial Infarction (Heart Attack): Classification

According to ECG manifestations, acute coronary syndrome (AKS; acute coronary syndrome, ACS) is classified as follows (modified from):

  • Non-ST elevation
    • Unstable angina* (UA; ” chest tightness”/heart pain with inconsistent symptoms) or
    • NSTEMI* * – English non-ST-elevation myocardial infarction. This type is smaller than a myocardial infarction with ST-segment elevation, but NSTEMI mostly affects high-risk patients with pre-damaged hearts. The long-term prognosis is also worse; or
    • NQMI* * – Non-Q-wave myocardial infarction; in 6 months, a Q-wave infarction occurs in about 30% of cases.
  • ST elevation
    • STEMI* * – English ST-elevation myocardial infarction – myocardial infarction with ST-segment elevation.
      • QMI – Q-prong infarction
      • NQMI – Non-Q-wave myocardial infarction; in 6 months, Q-wave myocardial infarction occurs in approximately 30% of cases

* CK-MB and troponin (TnT) not elevated* * CK-MB and troponin (TnT) elevated.

Classification of myocardial infarction.

Type Description
1 Spontaneous myocardial infarction secondary to ischemia (reduced blood flow or a complete loss of blood flow) in acute coronary syndrome (e.g., plaque rupture, erosion, fissure, or dissection)[most common type]
2 Secondary myocardial infarction due to ischemia (with necrosis) because of increased oxygen demand or decreased oxygen supply (e.g., coronary endothelial dysfunction, coronary artery spasm, coronary embolism, tachy/brady arrhythmias, hypotension and hypertension (high blood pressure) with or without left ventricular hypertrophy (LVH), anemia (anemia), respiratory insufficiency)* .
3 Sudden cardiac death (PHT) with cardiac arrest in:

  • Clinical symptoms,
  • ECG changes (ST elevation or left bundle branch block (LSB)), or.
  • Evidence of a thrombus (“blood clot”) of the coronary arteries/coronary arteries (angiography or autopsy).
4a Myocardial infarction associated with coronary intervention (percutaneous coronary intervention, PCI/dilatation of stenosed (narrowed) or completely occluded coronaries (arteries that surround the heart in a wreath-like fashion and supply blood to the heart muscle) (= revascularization; revascularization))
4b Myocardial infarction secondary to acute stent thrombosis (acute thrombotic occlusion of an artery within an implanted stent)
5 Myocardial infarction associated with bypass surgery (bridging of stenotic coronary vessels (narrowed coronary arteries) by means of a bypass (detour or bridging) procedure

* In the differentiation of type 1 patients, only the presence of relevant coronary stenoses seems to be important with regard to risk profile and prognosis. Type 1 and type 2 infarcts are prognostically comparable in the absence of obstructive coronary artery disease.

According to localization, myocardial infarctions can be divided into:

  • Anterior wall infarction
  • Posterior wall infarct
  • Lateral infarction or also lateral infarction
  • Septal infarction with
  • Inner and/or outer layer damage.