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A 58-year-old man with a history of smoking and hypertension presents to the emergency department with 45 minutes of central crushing chest pain radiating to his left arm, associated with sweating and nausea. His ECG shows 3 mm ST elevation in leads V2–V4. He is haemodynamically stable, with a heart rate of 92/min and a blood pressure of 132/84 mmHg. The nearest cardiac catheterisation laboratory is 100 minutes away by road.
Questions
a) What is the diagnosis, and which coronary artery is most likely occluded? (2 marks)
Diagnosis: anterior ST-elevation myocardial infarction (STEMI) — ST elevation in ≥2 contiguous precordial leads with ischaemic symptoms (1 mark). In a man of 58 the V2–V3 threshold is ≥2 mm, so 3 mm qualifies. The culprit vessel is the left anterior descending (LAD) artery, which supplies the anteroseptal territory represented by V1–V4 (1 mark).[1]
b) List the immediate (resuscitation-phase) management, with drug names, doses, and routes. (3 marks)
- Continuous cardiac monitoring, IV access, oxygen only if SpO₂ <90% (not routinely) (0.5 mark)
- Aspirin 300 mg orally, chewed (0.5 mark)
- A P2Y12 inhibitor — ticagrelor 180 mg loading (or clopidogrel 300–600 mg if ticagrelor unavailable/contraindicated) (0.5 mark)
- A parenteral anticoagulant — unfractionated heparin or enoxaparin per protocol (0.5 mark)
- Analgesia (small-dose IV opioid) if pain persists; sublingual GTN if not hypotensive/RV infarct (0.5 mark)
- Any correct mention of excluding aortic dissection before treatment (0.5 mark)[1][3]
c) Given the cath lab is 100 minutes away, what is the definitive reperfusion strategy, and why? (3 marks)
- Primary PCI is preferred only if achievable within 120 minutes of the STEMI diagnosis (1 mark)
- Since transfer would take 100 minutes and the patient presents within 12 hours of symptom onset, this is borderline/at the threshold — if PCI cannot be reliably delivered within 120 minutes once transfer, transfer, and door-to-balloon time are all accounted for, fibrinolysis (e.g. weight-based tenecteplase bolus) should be given instead, with the lytic bolus inside 10 minutes of the STEMI diagnosis, followed by immediate transfer for early or rescue angiography (1.5 marks)
- Rescue PCI is indicated if fibrinolysis fails (ST resolution under 50 percent or ongoing pain at 60–90 minutes); otherwise routine angiography 2–24 hours after lysis (0.5 mark)[2][3]
d) List three major complications this patient is at risk of in the first week, and how each presents. (2 marks)
Any three of (each worth up to 0.67 marks, capped at 2):
- Ventricular fibrillation — sudden collapse/cardiac arrest, the leading cause of early sudden death
- Cardiogenic shock — hypotension, cold peripheries, oliguria, pulmonary oedema
- Papillary muscle rupture / acute mitral regurgitation — new pansystolic murmur with sudden pulmonary oedema, peaking at day 2–7
- Ventricular septal rupture — new loud harsh pansystolic murmur with a thrill, biventricular failure, typically within the first 24 hours
- Free-wall rupture — sudden cardiac tamponade, often fatal, typically from 24–48 hours out to the first week
- Dressler syndrome — later (weeks), fever, pleuritic pain, pericardial rub[4]
References4ShowHide
- [1]Byrne RA, Rossello X, Coughlan JJ, et al. 2023 ESC Guidelines for the management of acute coronary syndromes Eur Heart J, 2023.PMID 37622654
- [2]Ibanez B, James S, Agewall S, et al. 2017 ESC Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation: The Task Force for the management of acute myocardial infarction in patients presenting with ST-segment elevation of the European Society of Cardiology (ESC) Eur Heart J, 2018.PMID 28886621
- [3]Rao SV, O'Donoghue ML, Ruel M, et al. 2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines Circulation, 2025.PMID 40014670
- [4]Meza-González YA, Manzur-Barbur MC, Ochoa-Díaz AF, et al. Untangling Mechanical Complications of Acute Myocardial Infarction JACC Case Rep, 2025.PMID 40185591