Week 2 - Pathophysiology of Thrombosis and Embolism

Question 1

Which factors are the body’s vascular system governed by?

Answer 1

• pressure gradient from arterial to venous
• resistance
• viscocity
• compliance of vessel (type - muscular, elastic, veins)

Question 2

What causes turbulence in vessels, forceful and unpredictable flow?

Answer 2

• blockage (thromboembolism, atheroma,)
• change in flow (hyperviscosity),
• external compression (tumour),
• inflammation of vessel wall

Question 3

What is Virchow’s triad?

Answer 3

3 facrtors that lead to thrombus formation. change in flow, change in constituents or change in vessel wall.

Question 4

How is a thrombus formed?

Answer 4

you need an endothelial injury, turbulent/static blood flow and hypercoagulability of blood. sticky collagen in wall exposed to platelets, forming thrombus

Question 5

what are favourable outcomes of a thrombus?

Answer 5

• sometimes resolve themselves.
• typically need thrombolysis,
• sometimes organisation occurs and new vessel forms.

Question 6

what are unfavourable outcomes of a thrombus?

Answer 6

causes death. propagation may occur - embolism

Question 7

What are common clinical scenarios of a thrombus?

Answer 7

• DVT,
• ischaemic limb (arterial thrombosis),
• myocardial infarction (thrombus forms on atheromatous plaque)

Question 8

What is an embolus?

Answer 8

detached intramuscular solid, liquid or gas

Question 9

What are types of embolus?

Answer 9

thrombus, systemic thromboembolus, venous thromboembolus (DVT origin),
-fat, gas, air, tumours, bone marrow, foreign bodies

Question 10

When can you get a gas embolus?

Answer 10

decompression sickness from N2. bubbles lodge in capillaries

Question 11

When can you get an air embolus?

Answer 11

• stab wound,
• central venous line insertion,
• surgery air bubble in circulation

Question 12

How does an amniotic fluid embolism occur?

Answer 12

during childbirth, keratin and skin cells get into maternal circulation and end up in lungs - reaction. mothers collapse and sometimes die

Question 13

What are risk factors for DVT and pulmonary embolism?

Answer 13

• anything from virchow’s triad.
• cardiac failure,
• severe trauma/burns (hypercoagulable state),
• nephrotic syndrome

Question 14

What is rheumatic disease?

Answer 14

disorder of immunity. polyarthritis in large limb joints.
RHD is caused by permanent damage of rheumatic fever

Question 15

What is pancarditis?

Answer 15

inflammation effecting entire heart - epicardium, myocardium and pericardium. can progress to chronic rheumatic disease.

Question 16

What can pancarditis lead to?

Answer 16

valvular abnormalities - necrosis of cusps/ chordae tendonae.

Question 17

Which valve does rheumatic heart disease effect?

Answer 17

mitral valve - rarely others. causes mitral stenosis.

Question 18

what is rheumatic fever?

Answer 18

presents with strep throat. theres a strong antibody reaction, which interracts with unknown antigens in connective tissue and can lead to heart damage.

Question 19

What signs do you see in the heart if rheumatic fever is present?

Answer 19

Aschoff bodies

Question 20

What are 3 forms of valvular heart disease?

Answer 20

• valvular stenosis
• valvular incompetence (failure to prevent blood reflux)
• vegetations (infective/thrombotic nodules on valve affecting mobility)

Question 21

What are lines of zahn?

Answer 21

alternating lines of white platelets and fibrin, and red blood cells, formed in a thrombus formed BEFORE death. areas of faster flowing blood have more lines of zahn

Question 22

What are Aschoff bodies?

Answer 22

Nodules of inflammatory cells, macrophages and necrosis active in heart