Acute Coronary Syndrome (ACS)

Acute Coronary Syndrome (ACS) represents the exacerbation of stable heart disease clinically manifested by the onset of myocardial infarction, the evolution of unstable angina, or sudden cardiac death. Pathological mechanisms such as plaque rupture, endothelial erosion, and thrombus formation in the occluded or stenotic coronary artery unify myocardial infarction and unstable angina under the umbrella term ACS, albeit with certain limitations. Additionally, the term ACS is introduced to prompt swift decision-making regarding the appropriateness of lytic therapy intervention before a definitive diagnosis of major myocardial infarction is established.

ACS encompasses a set of clinical signs or symptoms indicating the presence of unstable angina or acute myocardial infarction with or without ST-segment elevation. The term ACS may be used, without constituting a diagnosis, upon the initial contact of a patient with a physician, with the assumption that the patient with ACS is managed as someone suffering from acute myocardial infarction or unstable angina.

The treatment strategy for these patients involves alleviating myocardial ischemia without the use of thrombolytic agents, monitoring ECG changes and cardiac necrosis indicators (such as cardiac troponin, creatine kinase, and/or myoglobin). In the absence of cardiac necrosis indicators in the blood, ACS without ST-segment elevation is considered equivalent to unstable angina, or in case of elevated cardiac necrosis indicators, to subendocardial myocardial infarction (small myocardial infarction or non-ST-segment elevation myocardial infarction).

Rapid and reliable diagnosis of unstable angina and non-ST-segment elevation myocardial infarction requires determination of cardiac troponin levels, currently unavailable in most medical institutions. Therefore, when referring to ACS without ST-segment elevation, the terms unstable angina and non-ST-segment elevation myocardial infarction can be used interchangeably.

ACS with persistent ST-segment elevation, accompanied by chest pain or discomfort and/or new blockage of the left anterior descending artery, is usually caused by acute coronary occlusion. This condition constitutes an acute myocardial infarction and necessitates prompt reperfusion therapy – either by thrombolysis or direct coronary angioplasty.

In conclusion, understanding and managing acute coronary syndromes rely on accurate clinical detection and comprehensive assessment of changes in cardiac electrocardiography and cardiac necrosis indicator levels. Medical response should be swift and effective to provide appropriate treatment and achieve the best outcomes for patients with acute coronary syndromes.

“Protocol for the Management of Acute Coronary Syndrome (ACS)”