Pathophysiology of Thrombosis and Embolism

abnormal blood flow

stasis = stagnation of flow

turbulence = forceful unpredictable flow

vascular steal - blockage in subclavian artery, vertebral vascular circulation doesn’t get enough blood, stealing from subclavian artery

virchows triad = factors causing thrombosis

thrombosis is formation of a solid mass from the constituents of blood within the vascular system during life

clot - solidifies in tube (not in vessel anymore) or in external tissues, no longer in vessel

thrombus is INSIDE blood vessels

•Relationship between atheroma and thrombosis:

  arterial thrombosis most commonly superimposed on atheroma; Virchow’s triad

darker pink red blood cells

after major surgery or after trauma, can get hypercoagulability in that state

aneurysm - permanent localised dilatation, aortic aneurysm can lead to thrombus

favourable outcomes:

resolution - fibrin shrinks and gets digested by proteases

organisation- endothelial surface recovers thrombus, get small capillaries granulation tissue, macrophages and collagen deposition), restoration of blood flow and function /recanalisation

propagation - little bits of thrombus break off and embolise

embolism is movement of abnormal material in the bloodstream and its impaction in a vessel, blocking its lumen

embolus can be solid, liquid or gaseous mass

most embolism are dislodged thrombi = thromboembolism

if you have systemic thromboembolus usually you get infarction

Types of embolus

fat

gas

air

amniotic fluid

bone marrow

foreign bodies

rheumatic fever - disease of disordered immunity, commonly affects children 5-15 y/o, boys more than girls

pancarditis, inflammation affects everywhere in the heart (acute phase)

macrophages (activates) in the middle of this histology, seen in heart

valvular heart disease results from

valvular stenosis

incompetence/regurgitation/incompetency

vegetations : infective or thrombotic nodules (fibrin thrombus)

rheumatic fever can progress overtime to cause chronic rheumatic heart disease

principally fibrotic valvular disease

only cause of mitral stenosis