Arterial thrombosis

Question 1

what is an arterial thrombosis

Answer 1

blood clot which forms in an artery

Question 2

risk factors for arterial thrombosis

Answer 2

Factors that cause damage to endothelium, increase in foamy macrophages and platelet activation:
* Hypertension
* Smoking
* High cholesterol
Diabetes mellitus

Question 3

management of arterial thrombosis

Answer 3

aspirin and other anti platelets
modify risk factors for atheroscleoriss

Question 4

clinical presetation of arterial thrombosis

Answer 4

Peripheral arterial thrombosis: Sudden pain, pallor, coldness, pulselessness, and potential tissue necrosis in the limb.

Coronary thrombosis: Chest pain, shortness of breath, sweating, and possible heart attack (myocardial infarction).

Cerebral thrombosis: Sudden onset of weakness, speech difficulty, and loss of vision, possibly leading to a stroke.

Question 5

atherosclerosis steps

Answer 5

damage to endothelium causes recruitment of foamy macrophages rich in cholesterol resulting in cholesterol rich plaques

Question 6

what do stable plaques resul;t in

Answer 6

stable angina and intermittent claudicationwh

Question 7

what do unsatble plaques result in

Answer 7

stroke, unstable angina or MI

Question 8

durgs for arterial thrombosis

Answer 8

anti platelets

Question 9

drugs for venous thrombosis

Answer 9

anti coags

Question 10

characterisitcs of stable atherosclerotic plaques

Answer 10

hyalinsed and calcified

Question 11

unstable atherosclerotic plaques steps

Answer 11

Plaques rupture, platelets are recruited and cause acute thrombosis
Sudden onset of symptoms
Unstable angina or myocardial infarction (coronary arteries)
Stroke (cerebral arteries)

leads to acute organ ischaemia and infarctionn

Question 12

platelets and arterial thrombosis

Answer 12

Plaque ruptures – more likely in the high pressure environment of arteries

Platelet adheres to it – exposed endothelium and release of Von Willebrand factor

Platelets becomes activated - release granules that activate coagulation and recruit other platelets to developing platelet plug

Platelet aggregation via membrane glycoproteins

Question 13

what are foamy macrophages rich in

Answer 13

cholesterol

Question 14

what do platelets bind to subendothelial collagen via

Answer 14

glycoprotein 1b and vwf

Question 15

what do platelets attach to each other via

Answer 15

GPIIbIIIa and fibrinogen

Question 16

activation stage steps

Answer 16

Platelets alter their shape to expose more phospholipid on the surface-provides a greater surface area for coagulation activation and fibrin production to stabilise the clot.

Process is augmented by release of granules that further stimulate platelet activation eg Thrombin,Thromboxane A2 and ADP in order to recruit more platelets to the process.

This occurs via receptors to ADP etc on the platelet surface.

Question 17

MOA of aspirin

Answer 17

inhibits coco oxygenase which is necessary to produce thromboxane a2

Question 18

side effects of aspirin

Answer 18

. Bleeding

Blocks production of prostaglandins:

GI ulceration
Bronchospasm

Question 19

ADP receptor antagonists

Answer 19

clopidogrel, prasugrel

Question 20

Phosphodiesterase inhibitor

Answer 20

dipyridamole

increases production of camp which inhibits platelet aggregation

Question 21

GP IIb/IIIa inhibitors

Answer 21

abciximab

inhibit aggregation

Question 22

when should antiplatelets be stpped

Answer 22

7 days prior to elective operations

Question 23

arterial thrombosis conclusion

Answer 23

Causes organ ischaemia and is an inflammatory disorder instigated by damage to the endothelium

Platelets are central and are recruited to ruptured plaques

Antiplatelet drugs are useful in prevention

Question 24

venous thrombosis conclusion

Answer 24

Occurs in a low pressure system mainly by stasis

Platelets are not largely involved, and clots are rich in fibrin

Anticoagulants are useful in prevention