Acute Coronary Syndrome Quiz

See Section. Option D, ST-elevation myocardial infarction or STEMI, is included within acute coronary syndrome. Acute coronary syndrome is the clinical spectrum comprising STEMI, non-ST-elevation myocardial infarction and unstable angina. These conditions involve an acute myocardial ischaemic presentation, meaning that heart muscle is receiving insufficient oxygen for its needs. Plaque disruption with a coronary thrombus, a blood clot, is a common mechanism. Myocardial infarction involves injury with death of heart muscle, whereas unstable angina does not meet the criteria for infarction. The STEMI label reflects a diagnostic clinical and ECG pattern; it should not be treated as proof that every case has complete occlusion or necrosis through the entire ventricular wall.

Stable angina (B) is a chronic, predictable ischaemic symptom pattern and falls outside the acute coronary syndrome classification. Dilated cardiomyopathy (A) is enlargement and dysfunction of heart muscle rather than an ACS subtype, even when coronary disease contributes to the muscle damage. Aortic stenosis (C) is a narrowed outflow valve and may cause chest pain through increased myocardial demand, but is not itself ACS. Acute pericarditis (E) is inflammation of the sac around the heart; it can mimic ischaemic chest pain or ST changes but belongs to a different diagnosis.