Clinical Case Studies - Ischaemic Heart Disease

Question 1

What is atherosclerosis?

Answer 1

Chronic inflammation in the intima of arteries characterised by intimal thickening and lipid accumulation

Question 2

How is atherosclerosis formed?

Answer 2

• Endothelial injury
• LDL enters intima and is trapped in sub-intimal space
• LDL converted into modified & oxidised LDL, causing inflammation
• Macrophages take up modified &oxidised LDL, becoming foam cells (FATTY STREAK)
• Apoptosis of foam cells causes inflammation & cholesterol core of plaque
• Adhesion molecules on endothelium recruit more macrophages & T cells into plaque
• Vascular smooth muscle cells form FIBROUS CAP

Question 3

State at least 3 modifiable risk factors for atherosclerosis

Answer 3

• Type 2 diabetes mellitus
• hypertension
• hypercholesterolaemia
• smoking

Question 4

State 3 non-modifiable risk factors for atherosclerosis

Answer 4

• Male gender (less oestrogen/progesterone)
• increasing age
• family history

Question 5

What are the complications of atherosclerosis?

Answer 5

• Ischaemia from gradual obstruction
• Instant occlusion - rupture/haemorrhage/lipid embolus
• Aneurysm

Question 6

What are symptoms of MI?

Answer 6

• Chest pain
• Nausea
• Sweating
• Palpitations
• Can be silent in Diabetics

Question 7

Why does ischaemia cause these symptoms?

Answer 7

• Damage to myocardium
• Reduces cardiac output
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Question 8

What are signs of an MI?

Answer 8

• Raised JVP
• Increased pulse
• Pallor

Question 9

How would you investigate an MI?

Answer 9

• Bloods - troponin
• ECG - ST elevation/depression, inverted T waves, Q waves, LBBB
• CXR - cardiomegaly, pulmonary oedema, widening on mediastinum
• Angiography - with the view to perform PCI
• ECHO - signs of heart failure

Question 10

What are the complications of MI?

Answer 10

C PEAR DROP

• Pericarditis
• Emboli
• Aneursym formation
• Rupture of ventricle
• Dressler’s syndrome - autoimmune pericarditis
• Rupture of free wall
• Papillary muscle rupture

Question 11

What is Acute Coronary Syndrome?

Answer 11

Constellation of clinical symptoms that are compatible with acute myocardial ischaemia.

Divided into ST- elevated myocardial infarction (STEMI), non-ST elevated myocardial infarction (NSTEMI), and unstable angina (UA).

• STEMI → complete and prolonged occlusion of an coronary blood vessel + defined based on ECG criteria
• NSTEMI → severe coronary artery narrowing, transient occlusion, or microembolization. Defined by an elevation of Trop in the absence of ST elevation.
• UA → symptoms in the absence of elevated cardiac enzymes.