STEMI & nonSTEMI

Question 1

STEMI & nonSTEMI: Definition

Answer 1

• If stable and unstable angina are considered chronic versions of CAD (obv stable is more chronic and unstable is more acute), then STEMI and nonSTEMI can be considered very acute examples of CAD.
• IN MI, cardiac myocytes die due to myocardial ischarmia, usually a retrospective diagnosis made after troponin levels and/ or echocardiograms/ cardioangiogram (coronary angiography) are consulted

Question 2

STEMI and nonSTEMI: Aetiology

Answer 2

• nSTEMIs are usually a result of transient or near-complete occlusion of a coronary artery or acute factor that deprives the myocardium of oxygen
• different from a STEMI as there is not usually complete occlusion of the affected coronary artery

some non-atherosclerotic causes:

• coronary vasospasm without plaque rupture
• drug abuse (amphetamines, cocaine)
• dissection of the coronary artery related to defects of the vessel connective tissue
• thoratic aortic dissection

Question 3

STEMI and nonSTEMI: Risk factors

Answer 3

• Tobacco use
• Diabetes
• High blood pressure
• High blood cholesterol or triglyceride levels
• Family history of heart disease
• Older age
• Lack of exercise
• Obesity

Question 4

STEMI and nonSTEMI: Pathophysiology

Answer 4

• Common mechanism of all ACS (acute coronary syndrome) is rupture or erosion of fiberous cap of a coronary artery plaque
• this leads to platelet aggrigation and thrombus formation
• this causes vasoconstriction and distal thrombus embolisation

Question 5

STEMI and nonSTEMI: Cinical manifestations: key presentations, other symptoms and signs

Answer 5

• like other ACS conditions, new onset chest pain or chest pain at rest or worsening of pre existing angina
• associated nausia, vomiting, dyspnoea
• often retrosternal pain radiating to the L arm (and/ or lower jaw, neck, both arms, back, epigastrum)
• GTN trial leads to ongoing pain

Question 6

STEMI and nonSTEMI: Investigations (diagnosis): 1st line, gold standard & other

Answer 6

• see ECG picture attatched
• FBC
• troponin elevated
• CXR rule out DDx
• urgent coronary angiography in high risk patients

Question 7

STEMI and nonSTEMI: DDx

Answer 7

• Unstable angina (troponin levels distinguish)
• stable ischaemia/ angina (again, look at troponin)
• heart disease
• Aortic dissection
• PE
• peptic ulcer
• acute pericarditis
• psychological

Question 8

STEMI and nonSTEMI: Management

Answer 8

• Immediate management
  
  • Morphine
  • Nitrates (vasodialator)
  • Aspirin (anti-platelet)
  • Clopidogrel (anti-platelet)
• Asses need for PCI
• oxygen
• GTN
• anti-HTN
  
  • Beta-blocker
  • CCB
• Heparin (anti-coagulants)
• IIb/IIIa inhibitor (anti-platelets)