ACS meaning in Medical ?

Acute coronary syndrome (ACS) is a syndrome (a set of signs and symptoms) due to decreased blood flow in the coronary arteries such that part of the heart muscle is unable to function properly or dies. The most common symptom is centrally located chest pain, often radiating to the left shoulder or angle of the jaw, crushing, central and associated with nausea and sweating. Many people with acute coronary syndromes present with symptoms other than chest pain, particularly women, older patients, and patients with diabetes mellitus.

Acute coronary syndrome is subdivided in three scenarios depending on the duration of symptoms, the presence of ECG changes and blood test results: ST elevation myocardial infarction (STEMI, 30%), non-ST elevation myocardial infarction (NSTEMI, 25%), or unstable angina (38%). Generally, when symptoms occur for less than 30 minutes, it is unstable angina. When symptoms are prolonged for more than 30 minutes, the diagnosis is acute myocardial infarction.

ACS should be distinguished from stable angina, which develops during physical activity or stress and resolves at rest. In contrast with stable angina, unstable angina occurs suddenly, often at rest or with minimal exertion, or at lesser degrees of exertion than the individual's previous angina ("crescendo angina"). New-onset angina is also considered unstable angina, since it suggests a new problem in a coronary artery.