L3 Thrombosis-Embolism Flashcards
Solid Mass of blood constituents formed within vascular system responsible for nearly 50% of adult deaths?
Thrombus
Mass of material in vascular system mobile within vessel cable of blocking the lumen
Examples?
Embolism
Thromboembolism (from damage to blood vessel)
Fat Embolus (Fractured Bone)
Air Embolus
Amniotic Fluid
Tumor Fragment (Metastasis)
Septic Emboli
Foreign Body (Talc in IV drug Users)
What is Virchow’s Triad?
Changes in any 1/3 can lead to thrombosis:
- Endothelial Injury
- Abnormal Blood flow
- Hypercuogulbility
Intact versus Injured Epithelium?
Intact Epithelium
Anticoagulant
Fibrinolytic
Injured Epithelium:
Platelets adhere to exposed extracellular matrix
–> Endothelium becomes PRO CUAGULANT
Normal blood flow is __________ while during Stasis/Turbelence _______________
Normal flow is LAMNINAR:
Blood components flow centrally
Clear zone of plasma separating from endothelium
During Statis/Turbulence:
Platelets contact vessel wall
Inflow of clotting factor inhibitors slows
Promotes endothelial cell activation
Where do Arterial Thrombi usually occur?
Arterial Thrombi typically occur at:
site of endothelial injury
Bifurcation(turbulence)
Where do venous Thrombi usually occur?
Venous Thrombi occur at site of stasis
90% in Lower Extremities
Uncommon alteration of coagulation pathway that predisposes to thrombi with Primary (Genetic) Secondary (Acquired)
Hyper Coagulability
Alteration of coagulation pathway that predisposes to thrombi
Uncommon
Causes:
Primary (Genetic)
Secondary (Acquired)
_______________ are common in cardiac and aortic thrombosis and are used to determine is clot formed during patient’s life or postmorbid
Lines of Zahn:
Pale layers: Platelets mixed w/ Fibrin
Dark Layers: Red Blood cells
Common in cardiac or aortic thrombosis
Used to determine is clot formed during a patient’s life or post morbid
In which direction do arterial thrombi extend?
Extend in direction towards blood flow
In which direction do venous thrombi extend?
Extend in direction of blood flow
Propagating tail not well attached
Prone to fragmentation –> embolus
In which direction do venous thrombi extend?
Extend in direction of blood flow
Propagating tail not well attached
Prone to fragmentation –> embolus
Which type of thrombi is ALWAYS Occlusive?
Venous Thrombosis
Which type of thrombi are superimposed on Atherosclerotic lesion and lead to infarction of distal tissue?
Arterial Thrombosis
______________: form on wall of underlying structure
Heart chamber –> _____________
Aorta–> ___________________
Mural Thrombosis:
Form on wall of underlying structure
Heart chamber –> MI or Arrythmia
Aorta–> Atherosclerosis or Aneurysmal Dilation
Proximal vs. Distal DVT?
DISTAL Vein Thrombosis:
Deep Veins of Calf
PROXIMAL Vein Thrombosis:
Popliteal, Femoral, Iliac
Outcomes of DVT? (3)
Clinical Features of DVT?
Symptoms:
Pain
Swelling (Edema)
Redness (Erythema)
Signs:
Tenderness
Homan’s Sign (Sharp pain in calf upon dorsiflexion)
Increased calf diameter
30% of patients are Asymptomatic!!
Homan’s Sign is indicative of what?
Homan’s Sign (Sharp pain in calf upon dorsiflexion) is indicative of DEEP VEIN THROMBOSIS
Not done often due to risk of dislodging thrombosis
Phlegmasia Cerulea Dolens (‘___________’)
Very Rare
_________ Venous Thrombosis
Findings:
Venous _______
________ syndrome
Circulatory _______
Phlegmasia Cerulea Dolens (‘painful blue edema’)
Very Rare
Proximal Venous Thrombosis
Findings:
Venous Gangrene
Compartment syndrome
Circulatory Collapse
What is the investigation for DVT?
D-Dimer Blood Test:
D-Dimer: unique product of plasmin mediated breakdown of crosslinked fibrin
Negative D-Dimer + Low Clinical Probability (Well’s Score): excludes possibility of presence of a DVT
Treatment of Acute, Chronic and Massive DVT?
Acute:
- Subcutaneous LMW Heparin
- Unfractionated Heparin
Chronic
- Oral Anticoagulants:
- Warfarin
- Rivaroxaban
- Dabigatram
Massive
- Thrombolysis
- Surgical Thrombectomy
Prevention of Primary and Secondary DVT?
Prevention of DVT:
Primary
LMW Heparin
Movement after surgery
Compression Stockings
Secondary
Anticoagulation
Inferior Vena Cava Filter (to catch clot before entering heart)
From where do the majority of Pulmonary Emboli arrise?
DVT
Majority are clinically silent
Consequences of Pulmonary Embolism?
Respiratory Compromise
Lung not properly profused –>
Inflammation
Surfactant dysfunction
Atelectasis (collapse of lung)
hypoxemias
Hemodynamic Compromise
Resistance to flow –> rise in pulmonary blood pressure
–> acute right heart failure (Acute Cor Pulmonale)
–> pulmonary infarction (lung tissue death)
____________ straddles the bifurcation of pulmonary arteries and is found in autopsy
Saddle Embolus straddles the bifurcation of pulmonary arteries and is found in autopsy
________________:
Obstruction >50% of main or proximal artery
–> decreased cardiac output
–> right ventricular dilation (failure)
Example?
Clinical Presentation?
Acute Massive PE
Obstruction >50% of main or proximal artery
–> decreased cardiac output
–> right ventricular dilation (failure)
Saddle Embolus straddling the bifurcation of pulmonary arteries found in autopsy
Clinical Presentation:
Collapse
Central Chest Pain
Sudden Death
______________________
Small thrombi travel distally to occlude segmental pulmonary arteries
Clinical Signs?
Acute Small/ Medium PE
Small thrombi travels distally to occlude segmental pulmonary arteries
Clinical Signs:
Dyspnea
3 days later –> pleuritic (membrane surrounding lungs) chest pain
_________________
Exertional Dyspnea
Symptoms of right ventricular failure:
Peripheral Edema
Increased Juglar Venous Pressure (JVP)
Hepatomegaly
Chronic PE
Exertional Dyspnea
Symptoms of right ventricular failure:
Peripheral Edema
Increased Juglar Venous Pressure (JVP)
Hepatomegaly
Chronic occlusion of pulmonary microvasculature leads to ________________ and __________________
Chronic occlusion of pulmonary microvasculature leads to pulmonary hypertension and right heart failure
Symptoms of Pulmonary Embolism?
Symptoms:
Dyspnea –shortness of breath
Pleuritic chest pain –pain on taking a breath in
Hemoptysis –coughing up blood
Collapse
Signs of Pulmonary Embolism?
Signs:
Tachypnoea -fast breathing
Tachycardia -fast heart rate
Hypotension -low blood pressure
Fever - if infarcted
Right heart failure
Diagnosis of Pulmonary Embolism?
Diagnosis of PE
Arterial Blood Gas
D-Dimer Blood Test - Fibrin Degradation Product
BNP** and **Troponin Increase w/ Heart failure
ECG: Sinus tachycardia
Imaging:
Ventilation/ Perfusion Scan
CT Pulmonary Angiogram
Where do Systemic Emboli Arise?
Arises in:
Arteries
Left of Heart
Aortic Aneurism
Consequences of Systemic Emboli?
Tissue infarct
Transient Ischemic Attacks:
Cerebrovascular Accident (CVA)
__________________:
Shower of small embolisms to brain
Full recovery typical
Transient Ischemic Attacks:
Shower of small embolisms to brain
Full recovery typical
___________________\_: Large emboli in brain can cause stroke
Cerebrovascular Accident (CVA): Large emboli in brain can cause stroke
What can cause a systemic embolus to originate from a DVT?
Paradoxical Embolism :
Extremely Rare
Systemic embolism in venous part of circulation
Caused by abnormal blood transfer between the left and right sides of the heart
Patent Foramen Ovale
Atrial/Ventricular Septal Defect
_______________________: inherited or acquired defect of Haemostasias leading to disposition to thrombosis
Thrombophilia: inherited or acquired defect of Haemostasias leading to disposition to thrombosis
Autosomal DOMINANT
DVT and PE occur at early age, in unusual places
What is Factor V Leiden Mutation?
Factor V Leiden Mutation
Demographics:
Predominantly Caucasian
20-30% of DVT patients present w/
60% of those w/ recurrent DVT
Point mutation in gene encoding Factor V
Mutant form of Factor V cannot be degraded by activated Protein C
–> Anti-thrombotic counter-regulatory pathway lost
_______________
Predominantly Caucasian
Chromosome 11 mutation –> 30% increase in circulating Thrombin
Prothrombin Gene Mutation
Predominantly Caucasian
Chromosome 11 mutation –> 30% increase in circulating Thrombin
__________ is the precursor to thrombin
Prothrombin is the precursor to thrombin
___________ converts fibrinogen –> fibrin
Thrombin converts fibrinogen –> fibrin
Antithrombin III deficiency(AD), Protein C deficiency (AD), Protein S deficiency are examples of _______________
Antithrombin III deficiency(AD), Protein C deficiency (AD), Protein S deficiency are examples of Thrombophilias
What is Antiphospholipid Syndrome?
Diagnosis?
Clinical Presentation?
Antiphospholipid antibodies directed against phospholipids bound to plasma proteins
Pro-coagulant effect on Protein C, platelets, and tissue factor
Diagnosis:
Test for presence of anti-cardiolipin, anti-β2 glycoprotein 1
Clinical:
Arterial/ Venous Thrombosis
Repeated abortions due to placental thrombosis
Strokes
