Chapter 27 : Thrombosis 1 Flashcards
What is the function of Platelet derived Growth Factor?
It stimulates the migration and proliferation of smooth muscle cells and fibroblasts in the arterial intima.
What are the two important pathogenesis factors for Arterial Thrombosis?
Platelet deposition and thrombus formation
What are the risk factors for Arterial Thrombosis?
- Positive family history
- Male sex
- Hyperlipidaemia
- Hypertension
- Diabetes mellitus
- Gout
- Polycythaemia
- Cancer
- Hyperhomocysteinaemia
- Cigarette smoking
- ECG abnormalities
- Elevated CRP, IL6, fibrinogen, lipoprotein-associated phospholipase A2
- Lupus anticoagulant
- Collagen vascular diseases
- Behçet’s disease
- Malignancy
What are the components of Virchrow’s Triad?
1 Slowing down of blood flow.
2 Hypercoagulability of the blood.
3 Vessel wall damage.
What is the most common inherited cause of an increased risk of Venous Thrombosis?
Factor V Leiden (FVL) gene mutation
True or False? In Factor V Leiden (FVL) gene mutation, There is failure of activated protein C (APC) to prolong the activated partial thromboplastin time (APTT) test when added to plasma of patients with FVL, so the phenotype is sometimes referred to as ‘activated protein C resistance’.
TRUE!!
True or False? Factor V Leiden (FVL) gene mutation increases the risk of Arterial Thrombosis.
FALSE!! It does not increase the risk of arterial thrombosis.
What is the genetic mutation associated with Factor V Leiden deficiency ?
In the factor V Leiden mutation the Arg506Gln polymorphism leads to glutamine at position 506, with less efficient inactivation of factor V by APC and increased risk of thrombosis.
True or False? Antithrombin deficiency is Autosomal recessive.
FALSE!! It is Autosomal Dominant
True or False? In Antithrombin deficiency there are recurrent venous thromboses, usually starting in early adult life, and arterial thrombi may occur.
TRUE!!
Fill in the blanks. “ Infants may be born with homozygous Protein C deficiency and characteristically present with _____________.”
Disseminated intravascular coagulation (DIC) or purpura fulminans in infancy.
True or False? G20210A is a mutation in the promoter region of the prothrombin gene that has a prevalence of 2–3% in the population.
TRUE!!
What is a characteristic feature of Protein C and S deficiency?
Many patients develop SKIN NECROSIS as a result of dermal vessel occlusion when treated with warfarin alone, thought to be caused by a further reduction of protein C levels in the first day or two of warfarin therapy.
Fill in the blanks. “ In Prothrombin allele G20210A, there is an ____________ production of prothrombin
INCREASED
Fill in the blanks. “ The risk of venous thrombosis due to High Hyperhomocysteinaemia is only in the case of patients with _________.”
A deficiency of cystathione β-synthase (CBS).
Fill in the blanks. “ Homocysteine is derived from the dietary _________.”
Methionine
How is homocysteine normally removed?
It is normally removed by either either remethylation to methionine or conversion to cysteine via a trans-sulphuration pathway.
True or False? Classic homocystinuria is a rare autosomal recessive disorder caused by deficiency of CBS.
TRUE!!
What are the clinical features of CBS deficiency?
- Vascular disease
- Thrombosis
- Mental Retardation
- Lens Dislocation
5.Long slender fingers
What are the acquired risk factors for Hyperhomocysteinaemia?
- Deficiency of Vitamin B6 & folate 2. Drugs (e.g. ciclosporin)
- Renal damage
- Smoking
5 . Men and Post-menopausal women ( not acquired but mentioned)
Fill in the blanks. “ ____________is responsible for up to 50% of cases of Deep Vein Thrombosis and Pulmonary Embolism. “
Hospital-acquired thrombosis (HAT)
What is the time period of hospitalisation associated with Hospital- Acquired Thrombosis ( HAT) aka venous thromboembolism (VTE)?
90 days
Which patients are at risk for Post Operative venous thrombosis?
- Obese patients
2.Elderly - Patients with previous or family history of venous thrombosis.
- Patients with major abdominal or hip operations that were performed.
Fill in the blanks. “ Patients with carcinoma of the _____,_______ & ________ have increased risk of developing venous thrombosis.”
Ovary, brain and pancreas
Fill in the blanks. “ Oestrogen therapy, particularly high-dose therapy, is associated with increased plasma levels of factors ________.”
II
VII
VIII
IX
X
True or False? Oestrogen therapy is associated wit depressed levels of protein S and C and Tissue plasminogen activator in vessel wall.
TRUE!!
What is Antiphospholipid Syndrome?
The antiphospholipid syndrome (APS) can be defined as the occurrence of venous or arterial thrombosis and/or recur- rent miscarriage in association with laboratory evidence of persistent antiphospholipid antibody
What is the Antiphospholipid associated with Antiphospholipd syndrome APS ?
Lupus anticoagulant (LA)
How is Lupus Anticoagulant (LA ) identified?
It is identified by a prolonged plasma APTT which does not correct with a 50 : 50 mixture with normal plasma.
Dr. Lowe says prolonged PTT
Which test is used to confirm diagnosis oof Antiphospholipid syndrome?
Dilute Russell’s viper venom test ( DRVVT)
What are the important signs of Deep Vein Thrombosis?
- Unilateral thigh or calf swelling or tenderness
- Putting oedema
- The presence of collateral superficial non-varicose veins.
What is Homan’s sign?
Pain in the calf on flexing the ankle
What are the clinical features of Pulmonary embolism?
- Pleuritic chest pain
- Tachycardia
- Cough
- Dizziness
- Light- headedness
*Previous history of DVT - Immobilization for more than 2 days or recent (<4 weeks) surgery
- Haemoptysis
- Cancer
