Pathophysiology of thrombosis and embolism Flashcards
normal blood flow is described as
laminar
process of thrombosis.
endothelial injury, stasis or turbulent blood flow, hyper coagulability of blood
significance of Virchow’s triad.
change in blood vessel wall (eg atheromatous artery), blood constituents and pattern of blood flow. these are factors of thrombosis NOT clot
relationship between atheroma and thrombosis.
arterial thrombosis most commonly superimposed on atheroma due to virchows triad. hypercholesterolaemia due to virchows triad
factors causing thrombosis.
change in the heart eg vessel wall, hyper viscosity, post traumatic hyper-coagulability, stasis eg economy class syndrome, turbulence eg atheromatous plaque, aortic aneurysm
factors causing embolism.
defects in blood flow
atheroma, spasm, vasculitis, vascular steal syndrome, external compression, hyperviscosity, thromboembolism
clinical consequences of thrombosis
deep vein thrombosis, ischaemic limb, myocardium infarction
outcomes of thrombosis
resolution, organisation, recanalisation
outcomes of thrombosis
resolution, organisation, recanalisation, death, propagation
embolus
detached intravascular solid, liquid or gaseous mass. most are dislodged thrombi
types of embolus
systemic thromboembolus, venous thromboembolus, fat embolus, gas embolus, tumour, trophoblast, septic material, amniotic fluid, bone marrow, foreign bodies
mural thrombus
thrombus of the heart
systemic thromboembolus
travel to other sites eg lower limbs or brain. consequences depend on vulnerability of affected tissues to ischaemia, calibre of occluded vessel, collateral circulation but usually infarction occurs
consequences of pulmonary thromboembolism
depends on size of embolus but can be silent, pulmonary haemorrhage/infarction, right heart failure, sudden death. multiple PE over time leads to pulmonary hypertension and right ventricular failure
risk factors for DVT and pulmonary thromboembolism
cardiac failure, severe trauma or burns, post op, nephrotic syndrome, disseminated malignancy, oral contraceptive pill, elderly, bed rest, obesity
fat embolus
bits of fat get from the fractures thrown into the circulation after major fractures of bone. can affect the brain, kidneys or skin if get into systemic circulation
gas embolus
decompression sickness (nitrogen as bubbles in capillaries), air embolus (head and neck wounds, surgery, CV lines)
rheumatic fever
disease of disordered immunity, inflammatory changes in the heart and joints sometimes neurological symptoms
presenting feature of rheumatic fever
presenting feature is painful polyarthritis of large joints plus skin rashes and fever. pancarditis in acute phase, heart murmurs common. recent sore throat
valvular heart disease
valvular stenosis, valvular incompetence/ regurgitation, vegetations
valvular stenosis,
valve thickened/ calcified and obstructs normal blood flow into chamber or vessel
valvular incompetence/ regurgitation
valve loses normal function and fails to prevent reflux of blood after contraction of cardiac chamber
vegetations
infective or thrombotic nodules develop on valve leaflets impairing normal valve mobility and may embolise
rheumatic heart disease
pancarditis in acute rheumatic fever can progress into rheumatic heart disease manifesting as valvular abnormalities. characterised by fibrotic valvular disease involving the mitral valve- leaflet thickening, commissural fusion and shortening, thickening and fusion of chordae tendinae
mitral stenosis cause
rheumatic heart disease
