Pathology: circulatory disorders Flashcards
describe artery structure
Three layer structure
Inner layer- tunica intima
Middle layer- tunica media
Outer layer- tunica adventitia
what is atherosclerosis
A slow progressive intimal disease of large to medium sized muscular and elastic arteries
It results in elevated or occlusive intimal based lesions
The lesions or plaques are composed of lipids, smooth muscle cells and ECM
what are some non modifiable risk factors for atherosclerosis
genetic abnormalities
family history
increasing age
male gender
what are some modifiable risk factors for atherosclerosis
Hyperlipidaemia Hypertension Smoking Diabetes Inflammation
what is the pathogenesis of atherosclerosis
1) In the first response we get monocyte/platelet adhesion
2) The monocytes-> macrophages and secret cytokines and take up lipids in the blood stream
3) The macrophage now continues to take up lipids and smooth muscle leading to the formation of a atheromatous plaque
what is the sequence of atherosclerosis
Normal artery Fatty streak Fibrofatty artery Advanced vulnerable plaque Clinical stenosis- about 70% bloackage
what can atherosclerosis lead to
gradual mechanical obstruction to flow
plaque rupture
weakening of the vessel
what are major consequences in atherosclerosis
if in the coronary heart arteries- ischameic heart disease, angina
if in the aorta- aortic aneurysm
if in the mesenteric artery’s- bowel ischamia
if we get atherosclerosis in the coronary arteries what can it lead to
angina, MI
ischaemic heart disease
if we get atherosclerosis in the aorta what can it lead to
aortic aneurysm
if we get atherosclerosis in the mesenteric arteries what can it lead to
bowel ischaemia
what is age related vascular changes called
arteriosclerosis
what do we see as a patient ages in the arteries
thickening of the intimate
scarring of the media
fragmentation of the lamina
calcification
how can hyperglycaemia damage the vessel
• ROS formed
• Decreased NO
• Formation of advanced glycation end products
• Activation of inflammatory pathways
Promotion of thrombosis and atherosclerosis
what are the consequences of diabetic vascular disease
Microangiopathy Haemorrhage Hypertension Atherosclerosis MI Nephrosclerosis Islet cell loss Gangrene Peripheral vascular atherosclerosis
what is giant cell arteritis
it is also known as temporal/cranial arteritis depending on the vessel
chronic vasculitis of large/medium sized vessels
when do we see giant cell arteritis
hardly ever occurs in someone less than 50
what are the clinical signs and symptoms of giant cell arteritis
new headache- temporal tenderness, enlarged artery
jaw claudication
visual symptoms- amaurosis fugax
non descriptive eg flu, body ache
what is amaurosis fugax
blindness like curtains coming down on the eyes
what should the GDP do if we suspect GCA
seek advice
treat with oral steroids glucocorticoids
40-60mg prednisolone daily
what are tests we can do if we suspect giant cell arteritis
ESR- raised over >100mm/hr
CRP raised
haematology- normochromic normocytic anaemia
temporal artery biopsy- at least 1cm or longer within 7 days of treatment
what can giant cell arteritis lead to
retinal arterial occlusion- permanent partial/complete loss of vision in one or both eyes
if other branches are affected what can giant cell arteritis lead to
cerebral ischameia
mesenteric ischaemia
aneurysms
what is an aneurysm
localised, permanent abnormal dilations of a blood vessel
what are the types of aneurysms
Atherosclerotic Dissecting Berry Microaneurysms Syphilitic Mycotic False
describe atherosclerotic aneurysms
most common in elderly
what is the main risk factor for rupture of the atherosclerotic aneurysm
increase in the size of the aneurysm
if the aneurysm is 4-5cm what is the percentage rupture rate
1%
if the aneurysm is 5-6cm what is the percentage rupture rate
11%
if the aneurysm is >6cm what is the percentage rupture rate
25% risk
how can we detect an aneurysm
by ultrasound
how can the aneurysm be repaired
endovascularly
what are the complications of an aneurysm
the rupture causing retroperitoneal haemorrhage
what is a dissecting aneurysm
when blood gets tracked between the layers
what is a berry aneurysm
circle of willis- where small saccular lesions develop at sites of arterial bifurcations
where is berry aneurysm found commonly
in hypertensive pts
what can berry aneurysms cause
subarachnoid haemorrhages
describe micro aneurysms
occur in hypertensive patients
rupture causes intracerebral haemorrhage
what is a charcot bouchard aneurysm
occur in intracerebral capillaries in high BP pts
what can cause diabetic retinopathy
retinal microanuerysms
describe syphilitic aneurysms
occur in tertiary syphilis
occurs in the ascending thoracic aorta
causes ischamic medial damage fibrosis and loss of elasticity
describe mycotic aneurysms
rare
weakening go the arterial wall secondary to bacterial/fungal infection
how do organisms enter the media in mycotic aneurysms
from the vasa vasorum
where is mycotic aneurysms commonly found
in cerebral arteries
describe false aneurysms
blood filled space around the vessel following trauma
whams in contained in the adventitial tissue in false aneurysms
the haematoma
when is false aneurysms seen
following femoral artery puncture during angioplasty
definition of thrombosis
clotting in an abnormal situation leading to harm or injury
what is a thrombus
a solid mass or plug of blood constituents formed within the heart or blood vessels during life
what factors contribute to a thrombosis formation
virchows triad
what is virchows triad
endothelial injury
abnormal blood flow
hyper coagulability
what is abnormal blood flow
non laminar blood flow
what is venous thrombosis
stasis is the dominant mechanism
occurs at sites of stasis eg deep veins of legs
describe arterial thrombosis
endothelial injury to turbulent blood flow
what happens after thrombus formation
Propagation
Dissolution- dissolves from anti coagulation factors
Organisation- absorbed into the BV wall
Recanalization- new vascular channels open up inside the thrombus
Embolization- formation of a detached intravascular solid liquid or gas mass that is carried by the blood to a site far away from the origin leading to vascular occlusion
what is a thromboemboli
Embolus derived from part of a dislodged thrombus
what is venous emboli
From the venous system common legs leading to pulmonary embolism
what is arterial systemic emboli
emboli leading into the Arterial system to the brain, limbs and organs
what is a paradoxical embolism
Is when you have a embolus in the venous system and it lodges itself by bypassing the lungs by going through a defect in the heart
describe pulmonary embolism
uptown 60000 deaths per year from this
how does pulmonary embolism occur
1) Fragmentation of the DVT
2) Embolus enters the IVC
3) Passes through the right heart
4) Impaction and occlusion in pulmonary circ
what are the causes of pulmonary embolism
thromboembolic in origin usually
what is the classic history of pulmonary embolism
Sudden onset
Dyspnoea
Hypoxia
Tachycardic
how do we reduce the chance of pulmonary embolism forming
walking around a lot
drink a lot of water
TED stockings
anti coagulants
describe systemic thromboembolism
Occurs within the arterial circulation
Can come from other sources eg aortic aneurysms thrombus
Atherosclerotic thrombus
Paradoxical embolism
