FFinalistSouthampton · 2027
Acute care
AKT · Acute care/Cardiac & respiratory

Acute coronary syndrome

Coronary plaque rupture → ischaemia/infarction (STEMI/NSTEMI/UA)

Overview

A spectrum from unstable angina through NSTEMI to STEMI, driven by coronary plaque rupture and thrombosis. The pivotal split is the ECG/troponin: STEMI needs immediate reperfusion; NSTEMI/UA are risk-stratified and managed medically ± angiography.

Recognise

  • Central crushing chest pain ± radiation to arm/jaw, sweating, nausea, dyspnoea
  • STEMI: ST elevation / new LBBB
  • NSTEMI: ischaemic ECG changes + raised troponin · Unstable angina: pain at rest, troponin negative

Red flags

  • Ongoing pain, haemodynamic instability, arrhythmia, acute heart failure → high-risk, urgent cardiology

Differentials & how to tell them apart

Pulmonary embolismpleuritic pain, hypoxia, risk factors; ECG sinus tachy/S1Q3T3; troponin may rise but D-dimer/CTPA
Aortic dissectiontearing pain radiating to back, BP differential — do NOT anticoagulate
Pericarditispleuritic, positional pain, saddle ST elevation, friction rub
GORD/musculoskeletalno ischaemic ECG/troponin

Investigations

ECG within 10 min (repeat), serial high-sensitivity troponin, CXR, bloods; coronary angiography for STEMI/high-risk NSTEMI.

Management

Aspirin 300 mg + 2nd antiplatelet; STEMI → primary PCI (or thrombolysis if PCI unavailable)

  1. 1MONA where appropriate (morphine, O2 if hypoxic, nitrates if not hypotensive, aspirin 300 mg) + second antiplatelet. Get the ECG.Gate: STEMI → primary PCI within 120 min of first medical contact; if PCI not available in time → thrombolysis
  2. 2NSTEMI/UA: anticoagulate, risk-stratify (GRACE); high-risk → early angiography. Secondary prevention: dual antiplatelet, statin, ACE-i, beta-blocker, cardiac rehab.
Aspirin 300 mg + 2nd antiplatelet — dual antiplatelet (e.g. ticagrelor/clopidogrel/prasugrel)
Anticoagulant (fondaparinux/heparin) — NSTEMI/UA per pathway
Analgesia (morphine), GTN, O2 only if hypoxic — symptomatic; nitrates avoided if hypotensive/RV infarct

Key points

Avoid nitrates if hypotensive or in right-ventricular (inferior) infarction. Routine high-flow O2 is harmful if not hypoxic. Posterior MI = ST depression V1–V3 with tall R waves.

Monitor & prognosis

Continuous ECG, serial troponin, for arrhythmia/heart failure; secondary-prevention adherence.

Time-dependent — "time is myocardium"; better with early reperfusion.

Source: NICE NG185 (acute coronary syndromes)