Orris
Reading File
analyse_media
Finding Sources
Finding Sources
Reading File
Finding Sources
Here is a complete, textbook-backed answer to Q22:

Q22 - Complete Answer

a. Diagnosis (3 marks)

Acute Anterolateral ST-Elevation Myocardial Infarction (STEMI)
ECG findings supporting this diagnosis:
  • ST-segment elevation in leads V1-V4 (anterior/septal territory) and leads I and aVL (lateral territory)
  • Reciprocal ST depression in the inferior leads (II, III, aVF) - this is a hallmark finding
  • Normal sinus rhythm
Clinical correlation: The ECG changes perfectly fit her presentation - crushing central chest pain radiating to the left arm, nausea, light-headedness, onset at rest, 62-year-old female with HTN and hyperlipidaemia (both major risk factors). The culprit vessel is most likely the Left Anterior Descending (LAD) artery.

b. Drugs used to manage STEMI (3 marks)

Per the Textbook of Family Medicine (Table 27-18, Acute Pharmacologic Therapy of STEMI) and Fuster and Hurst's The Heart, the following drugs are used:
1. Antiplatelet agents (dual antiplatelet therapy - DAPT):
  • Aspirin - chewable, 162-325 mg loading dose
  • P2Y12 inhibitor - either Clopidogrel (600 mg), Prasugrel (60 mg), or Ticagrelor (180 mg) - loaded as soon as possible or at time of PCI
2. Anticoagulant:
  • Unfractionated Heparin (UFH) ± GP IIb/IIIa inhibitors, or Bivalirudin
3. Anti-ischemic / Symptom relief:
  • Morphine sulfate - for pain control
  • Sublingual/IV Nitroglycerin (Nitrates) - for chest pain if BP permits (avoid if BP low or phosphodiesterase inhibitor used)
  • Beta-blockers (e.g., Metoprolol) - within 24 hours if no contraindications; reduces myocardial oxygen demand
4. Adjunctive / Cardioprotective:
  • High-intensity Statin (e.g., Atorvastatin 80 mg)
  • ACE Inhibitor - especially with anterior MI, reduced EF (<40%), or heart failure
  • Reperfusion therapy - Primary PCI is the gold standard; if PCI unavailable within 120 min, use fibrinolytics (e.g., Tenecteplase, Alteplase)

c. Two Differential Diagnoses (3 marks)

The following two differentials are the most important to exclude before treating as STEMI (both cited in Rosen's Emergency Medicine and Schwartz's Principles of Surgery):
1. Aortic Dissection
  • Can mimic STEMI with severe chest pain
  • Classically described as tearing/ripping pain radiating to the back
  • Critically important to exclude before giving fibrinolytics (fibrinolytics are contraindicated in aortic dissection)
  • Differentiated by: pulse/BP differential between arms, widened mediastinum on CXR, CT aortography
2. Acute Pericarditis
  • Presents with chest pain and can show ST elevation on ECG
  • Key differences: pain is positional (worse lying down, relieved sitting forward), pleuritic in nature
  • ECG shows diffuse saddle-shaped ST elevation with PR depression (not the localised pattern with reciprocal changes seen in STEMI)
  • A pericardial friction rub may be audible
Other acceptable differentials include: Pulmonary Embolism (PE), Myocarditis, Takotsubo (stress) cardiomyopathy, or oesophageal spasm.
Quick Memory Aid (MONA + Antiplatelets):
  • M - Morphine
  • O - Oxygen (if SpO2 <90%)
  • N - Nitrates
  • A - Aspirin + second antiplatelet
  • Plus: Heparin, Beta-blocker, Statin, ACE inhibitor, and urgent reperfusion (PCI/thrombolytics)
This is a shared conversation. Sign in to Orris to start your own chat.