What does the term 'acute coronary syndrome' encompass?

The term 'acute coronary syndrome' (ACS) refers specifically to a range of conditions that result from a sudden reduction or blockage of blood flow to the heart, primarily due to the rupture of an atherosclerotic plaque and subsequent thrombosis. This leads to conditions such as unstable angina and myocardial infarction (heart attack).

Unstable angina is characterized by chest pain that occurs at rest or with minimal exertion and is a warning sign of an impending heart attack. Myocardial infarction occurs when blood flow to a part of the heart is completely obstructed, resulting in tissue damage. Together, these conditions highlight the urgency and critical nature of ACS, underscoring the need for immediate medical intervention.

In contrast, stable angina pectoris is a condition in which chest pain occurs predictably with exertion and is not classified under ACS because it does not represent an acute event but rather a manageable chronic condition. Heart valve diseases and heart arrhythmias refer to other categories of cardiac dysfunctions that are not directly related to the acute onset of reduced coronary blood flow associated with ACS.