Normal or nonspecific (e.g., ST depression, loss of R wave, T-wave inversion).Affects the full thickness of the myocardium ( transmural infarction).Classically due to complete occlusion of a coronary artery.Affects the inner layer of the heart ( subendocardial infarction).Classically due to partial occlusion of a coronary artery.Partial occlusion of coronary vessel → decreased blood supply → ischemic symptoms without infarction.Autonomic symptoms may be present: diaphoresis, syncope, palpitations, nausea, and/or vomiting.Severe, persistent, and/or worsening ( crescendo angina).Occurring at rest/with minimal exertion and is usually not relieved by rest or nitroglycerin.Symptoms are not reproducible/predictable.Acute myocardial ischemia that is severe enough to cause ST-segment elevations on ECG.

Acute myocardial ischemia that is severe enough to cause detectable quantities of myocardial injury biomarkers but without ST-segment elevations on ECG.Acute myocardial ischemia that is not severe enough to cause detectable quantities of myocardial injury biomarkers or ST-segment elevations on ECG.

ST-segment elevation myocardial infarction ( STEMI) Non-ST-segment elevation myocardial infarction ( NSTEMI) Overview of acute coronary syndrome ( ACS) See “ Myocardial infarction” for more details regarding, e.g., histopathology and long-term management. This article concerns the initial management of ACS patients. Adjunctive therapy (e.g., beta blockers, oxygen) helps reduce symptoms and can have a positive impact on mortality. All ACS patients receive dual antiplatelet therapy and initially anticoagulation. The timing and necessity of revascularization therapy in NSTE-ACS is determined based on multiple risk factors. STE-ACS patients require immediate revascularization therapy with percutaneous coronary intervention ( PCI) or fibrinolytic therapy. Depending on serum levels of cardiac troponin (cTn), NSTE-ACS can be categorized as NSTEMI or unstable angina (UA). Based on ECG findings, patients are categorized into those with ST-elevation ( STE-ACS) or non- ST-elevation ACS ( NSTE-ACS). Clinical findings (e.g., onset and characteristics of pain, patient history) in combination with ECG and troponin are the mainstays of diagnosis. Acute coronary syndrome ( ACS) is the clinical manifestation of myocardial infarct and commonly the default working diagnosis in patients with new-onset chest pain suspected to be of cardiac ischemic origin.

Class iii angina