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Flashcards in Thrombotic disorders Deck (15):

Contrast arterial and venous thrombi

arterial thrombi: platelet rich white clots formed under high shear stress, generally occlusive and lead to infarction

venous thrombi: fibrin rich red clots that occur in areas of venous stasis and lead to edema, swelling, pain, and inflammation


What is a paradoxical embolus?

embolus originating in a vein that bypasses the lung and enters the arterial circulation via a patent ductus arteriosis or atrial septal defect


In the formation of arterial atherosclerotic plaques, increased endothelial expression of VCAM has three major effects:

1. recruits inflammatory cells
2. stimulates cytokine release, lipid oxidation, uptake by macrophages
3. stimulates SMC proliferation


List risk factors for both venous and arterial thrombosis

hyperhomocysteinemia, heparin-induced thrombocytopenia, and antiphospholipid syndrome/lupus anticoagulants


List the three factors in Virchow's triad (risks for venous thrombi)

- venous stasis
- endothelial abnormalities
- intrinsic hypercoagulability of blood (ex factor V Leiden, AT3 deficeincey, SLE, DIC)


Lupus anticoagulants are phospholipid-dependent antibodies that inhibit
in vitro coagulation but are associated with ______ in vitro

arterial and venous thrombi- NOT bleeding


List two examples of targets of anti-phospholipid antibodies:

cardiolipin, B2 glycoprotein I


Describe antiphospholipid syndrome

the presence of persistent antiphospholipid antibodies in association with a syndrome of arterial and/or venous thrombosis, recurrent fetal wastage, and autoimmune thrombocytopenia


Describe the mechanism of HIT

moderate to severe, late
onset thrombocytopenia due to development of a heparin-dependent antibody that is associated with an increased risk of thrombosis

mechanism: PF4 binds heparin, forming neoantigens that cause Fc dependent platelet activation and release of platelet granules


What is appropriate treatment of HIT?

stop all heparin

give fondaparinux or argatroban


List five genetic syndromes associated with increased risk of VTE

- AT3 deficiency
- Protein C deficiency
- Protein S deficiency
- Factor V Leiden- most common
- Prothrombin G20210A polymorphism (autosomal dominant, increased levels of prothrombin antigen in plasma)


Increased levels of _______ is a risk factor for both arterial and venous thrombosis



What is standard therapy for uncomplicated DVT/PE?

5 days of heparin, transition to warfarin (or alternatively oral thrombin or Xa inhibitors)
3-6 months of therapy


Patients with ______ DVT are treated for longer periods of time due to increased risk of recurrence



List some therapies used for prophylaxis of VTE (as in hospitalized patients)

dabigatran, rivaroxaban
mechanical prophylaxis- compression stockings etc