Hemodynamics Flashcards
Deficiency in vW factor
Von Willebrand disease
Deficiency in Gp1b
Bernard Soulier syndrome
Deficiency of GpIIb-IIIa complex
Glanzmann thrombasthenia
Post-Mortem clot
Contains the lines of Zahn and is typically NOT attached to endothelial cell wall
Virchow’s triad: thrombus dev.
Stasis
Endothelial damage
Hypercoagulable state
Protection against thrombus formation
- Endothelial cells themselves block contact with sub endo collagen from interacting with platelets.
- PGI2
Heparin-like molecules
Activate antithrombin III
- block thrombin and inhibits coag factors
- produced by endothelial cells
TPA
- converts plasminogen -> plasmin which cleaves fibrin, or serum fibrinogen
- it destroys clotting factors
- blocks platelet aggregation
Thrombomodulin
- modulates thrombin to activate protein C which in turn inactivates factor V and VIII (important amplifying factors in the coag cascade)
Homocysteine in thrombosis
Increased levels -> damage endothelial cells
- this result from folate/B12 deficiency
Causes of increased hydrostatic pressure: 2 mechanisms and local vs. systemic
Impaired venous return - DVT (local) - CHF (systemic) Arteriolar dilation - heat - neurohumoral days regulation
Decrease in plasma oncotic pressure
- Albumin loss: nephrotic disease
- low albumin: liver damage, malnutrition (often both occur)
Na retention
Causes both increased hydrostatic pressure and decreased colloid osmotic pressure - results from primary kidney disorder, hypoperfusion, CHF et al.
Lympedema: 4 causes
Chronic inflammation (fibrosis)
Radiation
Infection
Auxiliary lymphadenectomy < über testable
Anasarca: definition and common location
Generalized widespread edema with tissue swelling
- subQ, periorbital, lungs, brain
Hyperemia vs. congestion
Hyperemia: active shunting of blood to a specific area
Congestion: increase local blood volume due to decreased outflow (passive)
Morphology of hyperemia and congestion
Lungs: dusky red, (acutely) engorged caps, focal intralviolar hemorrhage (chronically) thick, fibrotic septa, hemosiderin laden macs. (Heart failure cells)
Liver: nutmeg liver, small punctuate hemorrhages
Hemorrhage classification: (by size)
Petechiae: 1-3 mm
Purpura: 3-10 mm
Ecchymoses: >10 mm
Hematoma: a big ecchymoses
Alpha granules
Fibrinogen Fibronectin Factor V and VIII Platelet factor 4 (binds heparin) PDGF TGF-B
Dense granules
ADP ATP Ionized calcium Histamine Serotonin Epi
Activation of platelets
- vWF cross ridges with the platelet GPTNS to collagen sub endothelial tissue
- ionized Ca binds negatively charged surface GPTNS -> site for assembly of coagulation complexes
Events leading up to platelet plug (step 1)
- Thrombin binds receptor on platelet surface
- bound thrombin + ADP and TxA2 -> further aggregation
- contraction of platelet cytoskeleton (irreversible process)
Fibrin functions
Activated by thrombin
- crosslinks platelet plugin to a solid mesh work
- binds GpIIa-IIIb between two platelets
GpIIa-IIIb
Serves as fibronectin receptor crosslinking them into a solid mesh
Leukocytes in coagulation
- Adhere to platelets via P-selectins and contribute to inflammation
- thrombin - induces leukocyte/monocyte adhesion and generates fibrin spilt products
Vitamin K
Cofactor in the binding of factors II, VII, IX and X
- warfarin inhibits these processes
Function of thrombin: 5
Platelet activation Endothelial activation Monocyte activation Neutrophil adhesion Lymphocyte activation
Anti-thrombin III: source, action and clinical significance
Source: binding of HLMs on endo cells
Action: inhibits activity of thrombin and factors IX,X,XI and XII
Clinical sig: heparin enhances activation
Protein C and S: source and action
Source: vitamin K dependent proteins
Action: inhibits activated factors V and VII
Tissue factor pathway inhibitor
Source: produced by endothelium
Action: inactivates tissue factor VIIa complexes
TPA/PAI
TPA initiates degredation of fibrin: PAI inhibits TPA
a2-antitrypsin
Indus free plasmin in the blood to keep it from degrading
Alterations in normal bloodflow
Stasis and turbulence
Turbulence: atrial and cardiac thrombosis
- contributed to primarily by endo injury
Stasis: venous thrombosis
Ulceration of atherosclerotic plaques
- exposes sub endo collage -> thrombus formation
- results in turbulence
Aneurysms: effect
Local stasis
Acute MI
Stasis
Abnormal flow
Cardiac mural thrombi
Hyperviscosity (polycythemia)
Increased resistance and stasis
Sickle cell anemia
Vascular occlusion, stasis
4 common genetic hyper coagulable states
Factor V Leiden mutation
mutated prothrombin gene
Mutant THFr gene
Increased clotting factors (7,9,11)
Factor V Leiden mutation
COMMON, 2-15 Caucasians
- individual’s with recurrent DVT’s
- glu-> arg 506; factors resistant to Ca cleavage
- hetero: 5x
- homo: 50x
Prothrombin gene mutation
- Affects 1-2%
- single 3’ mutation
- increases prothrombin levels
- 3x fold increased risk
Young pt. presenting with thromboemboli
Must asses genetic susceptibility for clotting disorder
DIC
Platelets aggregate in microcirculation consuming clotting factors,
Schistiocytes form from trauma in vasculature. Diffuse activation of fibrinolysin
- trt underlying disease to fix DIC
Anti-phospholipid antibody syndrome
Cause: Abs form to epitopes on plasma proteins unveiled by phoslips.
Effect: hypercoagulable state
- false positive test for syphilis
Clinical manifestations: recurrent thrombosis, recurrent miscarriages, cardiac valve vegetations, tcytopenia, PE, pulmonary HTN
Postmortem clots
Chicken fat, no lines of Zahn, and non-adherent
Etiology: arterial thrombi
Ruptured atherosclerotic plaque, vasculitis, trauma
Etiology: mural thrombi (cardiac)
Abnormal cardiac contractions or endocaridal injury
Mural thrombi (aorta)
Ulcerated atherosclerotic plaque, aneurysmal dilation
Vegetations
Infective endocarditis, sterile endocarditis, SLE
PEs
- Generally silent due to small size and collateral circulation. Become organized
Medium emboli - pulmonary hemorrhage from vascular rupture
- infarction of left sided heart failure
Large/saddle - dead.
Etiology of most Systemic thromboemboli
80% arise from intracardiac mural thrombi
- 2/3 from left ventrical wall infarcts
- 1/3 from left atrial dilation/fibrillation
Fat/Marrow embolism
Fracture of long bones, tissue trauma
Histologically: looks like a bone marrow section
- results in free fatty acid toxicity, platelet activation, and granulocyte recruitment
Air emboli
- from surgery or decompression
- trt: with slow decompression
Amniotic fluid emboli: general
Tear in placental membrane, or rupture of uterine veins
- infusion of amniotic fluid, fetal tissue into maternal tissue
- diffuse alviolar damage
- pulmonary edema
- fibrin thrombi in vascular beds
Amniotic fluid emboli: clinical presentation
Sudden severe dyspnea, cyanosis, shock, neuroimpairment,
- if pt. survives; pulmonary edema, DIC
Infarction
Occlusion resulting in ischemia
- 40% of deaths in US resultant from CVD, most due to MI, cerebral infarction
- morbidity includes gangrene
- result is coagulative necrosis: except in brain -> liquifactive
Red infarcts
Venous occlusion,
- loose and dual circulation supplied tissue
White infarcts
Arterial occlusion
- solid organs with single arterial supply
Septic infarcts
Vegetation on cardiac valve embolizes
- microbes seed tissue
- abcess forms and occludes tissue
Tissue vulnerability to ischemia
- hypoxia sensitivity: brain (3-4 min), heart (20-30), fibroblasts (lots of hours)
- O2 content: anemia, cyanosis
Shock
Hypotension dude to either: decreased CO, or decreased blood volume
- impairs tissue perfusion and causes cellular hypoxia
Shock types: 5
anaphylactic: systemic vasodilation and increased vasc. Perm.
neurogenic: loss of vascular tone -> periph. Pooling
septic: inflammation, metabolic abnormalities, immune suppression organ dysfunction
hypovolemic:
Cardiogenic:
Toxic: superantigen mediated
Septic shock
- Inflammation compliment IL-16/8, NO, PAF -> systemic response: antiinflammatory signals (IL-1r inhibitor, IL-10)
- endo act
- metabolic abnormalities
- immune suppression
- organ dysfunction
Inflammation in septic shock
- Activation of neutrophils, monos, and endos
- TNF, interleukins (1,8 et al)
- PGEs
- activation of compliment
- factor XII
- immuneosuppression
Immunosuppressive effect in septic shock
The hyper state of infection results in a swing away from TH1 inflammatory cells to TH2 anti-inflammatory/immune response
- anti-inflammatory cytokines, IL-10, apoptosis et al.
Toxic shock
Very similar to septic shock, but mediated by superantigens
Factors effected by thrombomodulin
Throne-thombomodulin-Seige breaker-APC-factors V and VIII
Anti-thrombin III
- Binds heparin like molecules
- inhibits factors IX,X,XI,XII (anti thrombin III has the biggest number in it; inhibits the biggest numbers)
Activated Protein C (APC- siege breaker)
- initiates proteolysis of factors Va and VIIIa (Harry V and henry VIII)
Tissue factor pathway inhibitor
From endothelium; inactivates tissue factor-factor VIIa complex
Lupus anticoagulant
Hypercoagulant state; aka anti-phospholipid antibody syndrome
Alpha granules: components
Fibrinogen Fibronectin vWf P-selectins PDGF TGF-B
Dense granules: conponents
ADP Ca ATP Histamine Serotonin Epi