Pathophysiology of thrombosis & embolism Flashcards
what is embolism
an obstruction of an artery, typically by a clot of blood or air bubble
state 4 factors causing embolism
high blood pressure
atherosclerosis
high cholesterol
thrombosis
what is thrombosis
local coagulation in a part of the circulatory system
describe thrombosis
clotting of the blood in a part of the circulatory system
describe the process of thrombosis
it is the process of a blood clot forming in a blood vessel, this blood clot can be described as a thrombus
what is a thrombus
it is a blood clot formed in situ within the vascular system of the body and impedes blood flow
what is the result of a clot formed in a blood vessel in thrombosis
this clot can block or obstruct blood flow in the affected area, as well as cause serious complications if the clot moves to a crucial part of the circulatory system, such as the brain or the lungs
what does Virchow’s triad describe
3 broad categories of factors that are though to contribute to thrombosis
what are the 3 broad categories of Virchow’s triad that are thought to contribute to thrombosis
the states of blood flow
endothelial injury
hyper-coagubility
what is atheroma
the fatty material which forms deposits in the arteries
state a genetic condition which is a factor causing thrombosis
thrombophilia, this is a genetic condition where your blood has an increased tendency to clot
state an immune system disorder that is a factor causing thrombosis
anti-phospholipid syndrome is an immune system disorder that causes an increased risk of blood clots
what are factors causing thrombosis
infectious and inflammatory conditions
state an infectious condition that is a factor causing thrombosis
hepatitis
state an inflammatory condition that is a factor causing thrombosis
rheumatoid arthritis
what is normal blood flow
LAMINAR
what is abnormal blood flow
STASIS: stagnation of flow
TURBULENCE: forceful, unpredictable flow
what are defects in blood flow
thromboembolism atheroma hyper viscosity spasm external compression vasculitis vascular steal
what is Virchow’s triad
changes in the:
blood vessel wall
blood constituents
pattern of blood flow
what are the factors causing thrombosis
Virchow’s triad
define thrombosis
the formation of a solid mass from the constituents of blood within the vascular system during life
what do the consequences of thrombosis depend on
site
extent
collateral circulation
what are common clinical scenarios from presenting with thrombosis
deep vein thrombosis
ischaemic limb
myocardial infarction
what is the outcome of thrombosis
resolution
organisation/recanalisation
death
propagation leading to embolism
what is embolism
the movement of abnormal material in the bloodstream and its impaction in a vessel, blocking the lumen
what is a embolus
it is a detached intravascular solid, liquid or gaseous mass
what are most emboli
dislodged thrombi
what do factors causing embolism depend on
the type of embolus
what are types of thrombus embolus
systemic thromboembolus
and arterial thromboembolus
describe systemic thromboembolus
embolus that travels to a wide variety of sites, from the lower limbs commonly, to the brain and other organs
what do the consequences fro a systemic thromboembolus depend on
vulnerability of affected tissues to ischaemia,
calibre of occluded vessel,
collateral circulation but usually infarction occurs
describe a venous thromboembolus, a type of embolus
this thrombus originates from deep venous thromboses (lower limbs)
what are risk factors for deep vein thrombosis and pulmonary thromboembolism
cardiac failure severe trauma burns post-op post-partum nephrotic syndrome disseminated malignancy oral contraceptive older age bed rest immobilisation obesity past medical history of deep vein thrombosis
what is affected from a syndrome of fat embolism
brain
kidneys
skin
when do fat embolus occur
after major fractures
when do air embolus occur
head wounds
neck wounds
surgery
CV lines
what is amniotic fluid embolus the cause
collapse in childbirth
when are bone marrow embolus present
fractures
CPR
when is a foreign body embolus present
intravascular cannula tips
sutures
etc.
what are presenting features of rheumatic fever
flitting polyarthritis of large joints
skin rashes
fever
i.e. painful wrists, elbows, knees, ankles
who does rheumatic fever commonly affect
children aged 5-15 years
boys more than girls
where is rheumatic fever common
india, middle east, central Africa
where is rheumatic fever now rare
in Europe and north America
what is rheumatic fever
it is a disease of disordered immunity, it is inflammatory changes in the heart and joints
when aschoff body seen?
in the heart in acute rheumatic fever
what is an aschoff body
it is a focus of chronic inflammatory cells, necrosis and activated macrophages
what pathological problems result from valvular heart disease
valvular stenosis
valvular incompetence
valvular regurgitation
vegetations
what is virtually the only cause of mitral stenosis
rheumatic heart disease
what can cause mitral regurgitation, which is however most often due to ischaemic heart disease
rheumatic heart disease
what now only rarely causes aortic stenosis
rheumatic heart disease
what is aortic stenosis mostly due to
calcific aortic valve disease
