Acute Coronary Syndrome

Acute Coronary Syndrome (ACS) encompasses STEMI, NSTEMI, and unstable angina, caused by myocardial ischaemia due to coronary artery occlusion. Diagnosis is based on clinical presentation, serial ECGs, and cardiac biomarkers (troponin).

🎯 Key Learning Objectives

1. Distinguish between STEMI, NSTEMI, and unstable angina using ECG and troponin criteria.
2. Identify ECG patterns of infarction including ST-elevation, T-wave inversion, and ST-depression.
3. Implement immediate 'MONAC' management (Morphine, Oxygen, Nitrates, Aspirin, Clopidogrel).
4. Explain the indications for primary Percutaneous Coronary Intervention (PCI) versus fibrinolysis.
5. Recall long-term secondary prevention strategies (6A's: Aspirin, Antiplatelet, Anticoagulant, Atorvastatin, ACE-inhibitor, Atenolol/Beta-blocker).
6. Recognize complications of MI such as heart failure, arrhythmias, and cardiac rupture.

🔬 Pathophysiology

Rupture or erosion of an unstable atherosclerotic plaque leads to platelet aggregation and thrombus formation. This causes partial or total occlusion of the coronary artery, resulting in myocardial ischaemia or infarction (necrosis).

🩺 Clinical Features

🔬 Investigations

💊 Management

⚠️ Complications

⭐ High-Yield Pearls

• ST-elevation in II, III, aVF indicates an inferior MI via the Right Coronary Artery.
• Avoid nitrates in suspected right ventricular infarction due to preload dependence.
• New-onset Left Bundle Branch Block (LBBB) in the context of chest pain is treated as a STEMI.
• Troponin can be elevated in PE, sepsis, and renal failure, not just ACS.
• Dual antiplatelet therapy (DAPT) duration is typically 12 months post-ACS.

❓ Practice Questions