Complications Of Vascular Disease / Thromboembolic Disease

Question 1

Epidemiology of an Atheroma

Question 2

Pathogenesis of Atheroma

Answer 2

Complement cascade begins

First few days: Influx of neutrophils/acute inflammation

Restitution: Increase in macrophages, neutrophils die giving a yellow appearance

2-4 weeks: Fibroblasts lay down collagen

Question 3

What is arterial stenosis?

Answer 3

Narrowing of arterial lumen, reduces blood flow in systole

Common sites:
- Coronary arteries
- Carotid arteries (Stroke)
- Renal arteries (Hypertension and renal failure)
- Peripheral arteries (Lower limb ischaemia)

Question 4

What is an aneurysm, its common site of occurance and its complications?

Answer 4

Abnormal and persistent dilation of artery due to weakness in arterial wall

Common site: Distal abdominal aorta (above bifurcation)
- Turbulent blood flow, loss of elasticity

Complications:
- Rupture
- Thrombosis (plaque build up)
- Embolism (plaque breaks off)
- Infection

Question 5

What is arterial dissection and what is it associated with?

Answer 5

Tear in tunica media caused by flowing blood

False lumen can form in media and fill with blood, narrowing the artery

Sudden collapse, high mortality

Associated:
- Atheroma (most common in males)
- Hypertension
- Trauma
- Genetic condition (Marfans)
- Pregnancy

Question 6

Define Thrombosis and its pathophysiology:
- Coagulation cascade
- Favoured conditions (Virchow’s triad)

Answer 6

Blood clot that forms in an artery (build up of plaque) - excess intravascular coagulation

Coagulation cascade
- Intrinsic: Activation of factor XII, Measured with prothrombin time (PT)
- Extrinsic: Starts with TF, Measured with APTT
- End point: Prothrombin > Thrombin then Fibrinogen > Fibrin

Virchow’s Triad:
- Endothelial injury
- Turbulent blood flow (swirling of blood)
- Hypercoaguable blood (increased viscosity)

Question 7

Define an embolism and its pathophysiology:

Answer 7

Thrombus that has been transported through vessel and gotten stuck - mostly venous

Blocks blood flow causing ischaemia

Types of embolism:
- Air embolism
- Amniotic fluid embolism
- Fat embolism
- Tumour emboli
- Septic emboli

Question 8

Define ischaemia:

Answer 8

Insufficient blood supply therefore insufficient oxygen supply

No oxygen = no ATP

Question 9

Define infarction:

Answer 9

Death of tissue as a result of ischaemia