Circulatory Disorders Flashcards
What is a vascular occlusion?
Blockage of a blood vessel
What can a vascular occlusion result from?
- Thrombosis
- Embolism
- Atherosclerosis
- External compression
What does the severity of a vascular occlusion depend on?
- Type of tissue involved
- How quickly the occlusion occurs
- Availability of collateral circulation
What is a thrombus?
Solid mass of blood formed within the cardiovascular system involving; endothelial cells, platelets and coagulation cascade
What are some differences between patients suffering from arterial and a venous thrombus?
ARTERIAL:Old age, circulatory disorders, diabetic, smoker
VENOUS: may be any age, immobility (i.e. flights)
Name for the factors contributing to thrombus
Virchow’s triad
What are the factors that make up Virchow’s triad?
- Alteration to blood constituents
- Damage to endothelial lining
- Changes to normal blood flow
What is an embolism?
Where fragments of thrombus break off and travel through blood and cause an occlusion elsewhere
What are the lines of Zahn?
Alternating red and white blood cell deposits, operated along blood flow
Treatments for thrombus
Streptokinase
Aspirin
What is the mechanism of streptokinase?
Promotes formation of plasmin which breaks down the clot
What is the mechanism of aspirin?
Inhibits thromboxane thus inhibiting clot formation
What is atherosclerosis?
Damage to intima which causes narrow vessels and obstruction
What is arteriosclerosis?
Disease of media –> increased wall thickness and decreases elasticity –> hypertension
Main difference between atherosclerosis and arteriosclerosis
Atherosclerosis is a disease of the intima
Arteriosclerosis is a disease of the media
Where do plaques form?
Atheromatous plaques form in the intima of the artery
What kind of core do atheromatous plaques have?
Necrotic cores
What are the major components of atheromatous plaques?
- Cells
- ECM
- Lipid
- Calcification
Processes in plaque formation
Intimal thickening
Lipid accumulation
What is the name for coronary artery disease?
Ischaemic heart disease
What is a prominent feature of ischaemic heart disease?
Sudden death
Fixed risk factors of CAD
Age, males, positive family history
Modifiable risk factors of CAD
Smoking, obesity, diabetes, hypertension
3 causes of restricted blood supply to the heart
- Blockage
- Decrease in oxygenated flow
- Increased demand
Why may someone have an increased demand to the heart?
Increased cardiac output or they have have hypertrophy (enlarged heart)
Why may someone have a decrease in deoxygenated blood flow?
Anaemia, CO poisoning, hypotension
What is arteriogenesis?
Collateral vessel formation so that if an artery is occluded then blood can be diverted from other arteries to compensate
Treatments for an artery blockage?
Angioplasty
Stents
What is angioplasty?
When deflated ballon is then inflated in artery to squash the plaque flat
What is restenosis?
When after stenting, the blockage reforms over a period of time
What else can be done to stents to reduce blockages?
Drug elution from stints
What are some risks associated with stenting?
May not be safe long term and increased late stent thrombosis
