Acute coronary syndrome (ACS) is the clinical manifestation of coronary occlusion, due to atherosclerotic plaque rupture or thrombosis.
- ACS presents as unstable angina, NSTEMI, or STEMI.
- The outcome depends on the severity of the obstruction and which vessel is occluded.
Presentation
Unstable angina
Angina pectoris occurs due to insufficient oxygen supply to the heart.
- Stable angina is due to insufficient oxygen supply during increased demand (e.g. exercise)
- Unstable angina is due to insufficient oxygen supply without increased demand (i.e. rest)
Unstable angina is angina pectoris which:
- Appears at rest (>20min)
- New onset angina that is severe and progressive
- Any change in the characteristics of an existing stable angina (duration, frequency, onset, intensity, flavor)
It may appear with transient ECG changes (ST-elevation/depression, T-wave inversion).
NSTEMI
NSTEMI is MI limited to only the inner third of the myocardium (subendocardial MI), leading to necrosis.
- As myocardial necrosis is taking place, CK-MB and troponin-I/T elevation (<1.0ng/L) can be detected.
- NSTEMI produces no