Acute Coronary Artery Syndrome (ACS)

Acute Coronary Artery Syndrome (ACS) is a medical emergency and requires immediate hospital admission. ACS refers to a range of acute myocardial ischaemic states, which include:

  • Unstable angina and
  • Two forms of myocardial infarction in which heart muscle is damaged. These types are named according to the appearance of the EKG as non-ST segment elevation myocardial infarction (NSTEMI) and ST segment elevation myocardial infarction (STEMI).


  • Chest pain, which may be associated with sweating, nausea, vomiting, dyspnoea, fatigue, shortness of breath and palpitations.
  • Some patients, particularly the elderly and patients with diabetes, may not have chest pain. Patients from some ethnic groups may also present with atypical pains.
  • Physical examination is focused on the assessment of cardiac function and blood pressure  and on excluding important other causes.

Acute coronary syndromes (ACS) result from acute obstruction of a coronary artery. Consequences depend on degree and location of obstruction and range from unstable angina to non–ST-segment elevation MI (NSTEMI), ST-segment elevation MI (STEMI), and sudden cardiac death. Symptoms are similar in each of these syndromes (except sudden death) and include chest discomfort with or without dyspnea, nausea, and diaphoresis. Diagnosis is by ECG and the presence or absence of serologic markers. Treatment is antiplatelet drugs, anticoagulants, nitrates, β-blockers, and, for STEMI, emergency reperfusion via fibrinolytic drugs, percutaneous intervention, or, occasionally, coronary artery bypass graft surgery.




If the ECG confirms changes suggestive of a heart attack, medication is injected that dissolves blood clots obstructing the coronary arteries, or a Percutaneous Coronary Intervention (PCI) may be performed. Data suggest that rapid transfer and treatment is essential.


If the ECG does not show typical changes, the term "non-ST segment elevation ACS" is applied. The patient may still have suffered a "non-ST elevation MI" (NSTEMI). The accepted management of unstable angina and acute coronary syndrome is treatment with medications alone.