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Unformatted text preview: irchow’s Triad - Venous PE
1. Stasis of blood 2. EC disruption 3. Hypercoagulable Blood – Coagulation proteins Creates Red Clot - full of RBC Arterial Thrombosis
1. 2. 3. High flow/shear Collagen Normal blood White Clot of platelets, not RBC Paradoxes Paradoxes
• • • • Platelet aggregation studies with stasis Biomaterial surface is critical
months to occlude
(Virchow) Platelet concentration is small collagen, fibrinogen – early adhesion only collagen, GP platelet bonding rate is too slow Shear forces/bond strengths should rip off thrombus
GP Ib+vWF ~ 0.1 - 30 sec -> takes hours GP Activation, GP IIb/IIIa ~ minutes -> days • -> Occlusive thrombus should not occur -> not Heart attacks and strokes do not exist! Problem with previous work Problem A. B. C. Coagulation – No Shear Coagulation Normal arteries – Moderate shear Normal Diseased arteries – High shear Diseased For heart attacks Very High Shear Platelet thrombosis review
Activation is key - ASA/Plavix o Activation stimulated by shear -> “Shear History” of circulating platelets o Bag of reactants with vWF
o Parallel plate deposition
Velocity Vectors Transient VWF/Fibrinogen Activated Torque 2. Bound activated platelet...
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This note was uploaded on 02/08/2011 for the course ME 3141 taught by Professor Staff during the Fall '10 term at Georgia Institute of Technology.
- Fall '10