Ischaemic heart disease and acute coronary syndromes
This domain dominates clinical cardiology marks. It tests ECG interpretation under time pressure, reperfusion deadlines, antithrombotic choices and recognition of mechanical complications.
Diagnosis
- ECG within 10 minutes of first medical contact; repeat if non-diagnostic.
- STEMI: ST elevation of 1 mm or more in two contiguous limb leads, or 2 mm or more in V2-V3 in men aged 40 and over (2.5 mm in men under 40, 1.5 mm in women). Posterior MI shows ST depression with tall R waves in V1-V3.
- NSTEMI is defined by a rise and fall of high-sensitivity troponin with ischaemic features; unstable angina has ischaemia without troponin release. ESC 0/1-hour algorithms use absolute values and deltas.
Reperfusion and drugs
- Primary PCI within 120 minutes of first medical contact; if unachievable, fibrinolysis within 30 minutes of diagnosis and transfer for angiography.
- Aspirin loading plus a P2Y12 inhibitor (ticagrelor or prasugrel preferred where licensed) and parenteral anticoagulation; radial access reduces bleeding.
Risk and complications
- GRACE score guides invasive timing; Killip class predicts mortality.
- Day 1-5: ventricular arrhythmia. Day 3-5: free wall rupture, ventricular septal rupture, acute mitral regurgitation. Weeks 1-6: Dressler syndrome.
- Right ventricular infarction: inferior STEMI with hypotension, raised JVP and clear lungs; give fluids, avoid nitrates and diuretics.
Worked example
A 58-year-old with two hours of chest pain has inferior ST elevation, hypotension and ST elevation in V4R. This is right ventricular infarction. Volume loading and inotropes if needed, avoid nitrates, and proceed to primary PCI.
Traps
- Using troponin to diagnose STEMI; the ECG is the decision tool.
- Missing posterior MI because you only look for ST elevation.
- Nitrates in right ventricular infarction or recent sildenafil use.
- Forgetting MINOCA workup (CMR, thrombophilia, vasospasm) when coronaries are clean.