ACS dr harith.pdf

ACUTE CORONARY SYNDROME DR. HARITH AL-QAZAZ B.SC., M.SC., PH.D., R.PH. LINKS https://www.youtube.com/watch?v=C0BUPHYQ1h4 https://www.youtube.com/watch?v=j8rIAxeiHnk https://www.youtube.com/watch?v=9XWcc3CtTMQ...

ACUTE CORONARY SYNDROME DR. HARITH AL-QAZAZ B.SC., M.SC., PH.D., R.PH. LINKS https://www.youtube.com/watch?v=C0BUPHYQ1h4 https://www.youtube.com/watch?v=j8rIAxeiHnk https://www.youtube.com/watch?v=9XWcc3CtTMQ 2 1 DEFINITION Acute coronary syndrome (ACS) refers to a spectrum of clinical presentations ranging from those for ST-segment elevation myocardial infarction (STEMI) to presentations found in non–ST-segment elevation myocardial infarction (NSTEMI) or in unstable angina. In terms of pathology, ACS is almost always associated with rupture of an atherosclerotic plaque and partial or complete thrombosis of the infarct-related artery. ACS results primarily from diminished myocardial blood flow secondary to an occlusive or partially occlusive coronary artery thrombus. 3 CLASSIFICATION ACSs are classified according to (ECG) changes into (1) ST-segment-elevation ACS (STE ACS or STEMI) and (2) non–St segment-elevation ACS (NSTE ACS), which includes non–ST-segment elevation myocardial infarction (NSTE MI) and unstable angina (UA). Note: After a STEMI, pathologic Q waves are seen frequently on the ECG and usually indicate transmural MI. 4 2  5 6 3 PATHOPHYSIOLOGY Endothelial dysfunction, inflammation, and formation of fatty streaks contribute to development of atherosclerotic coronary artery plaques. Eventual plaque rupture and subsequent thrombus formation abruptly decreases myocardial blood flow and oxygen supply, leading to ischemia and, potentially, infarction. Atherosclerotic plaques that rupture typically have thin fibrous caps and tend to be nonobstructive, occluding