Thrombosis Flashcards Preview

Yr 3 - December lectures 2018 > Thrombosis > Flashcards

Flashcards in Thrombosis Deck (13)
Loading flashcards...
1

What can a bad clot lead to ?

DVT, PE

2

What characteristic features are seem in arterial thrombosis?

fatty streaks in arteries - we will already have some
narrowing of the lumen => plaque rupture
both obesity and smoking exacerbate this condition

3

How many deaths due to VTE occur in Europe?

about 543 454 = exceeds combined deaths due to AIDS, breast cancer, prostate cancer, transport accidents

4

What is the cascade of events with a DVT?

DVT = source clot that tends to occur in lower limb but can also occur in upper limb
=> can lead to a PE which can lead to death/ pulmonary hypertension and then onto death
=> also causes deep vein insufficiency => post-thrombotic syndrome => venous ulcers

5

What is the crude mortality in the elderly of DVT?

15-20% within 3 months of diagnosis

6

What is PTS?

Post-thrombotic syndrome= continuing burden
- after symptomatic DVT
- overall frequency is 20-50%
- severe PTS occurs in 5-10% of patients
pain, swelling and ulceration of the legs

7

What is virchow's triad?

- alterations in normal blood flow (stasis) - can be due to intrinsic pressure
- injuries to the vascular endothelium
- alterations in the constitution of the blood (hyper coagulability)

8

How much more likely is VT in pregnancy and why?

10x more likely
- state of hyper coagulability = increased clotting factors, reduced fibrinolysis, increased platelet adhesiveness = in preparation for birth

Venous stasis resulting from pressure of the gravid uterus on inferior vena cava and decreased venous tone
- may compress R iliac vein therefore always roll pregnancy women onto L side

9

Other than pregnancy when else is the risk of DVT increased?

when in hospital - 100 fold increased risk - give heparin (blood thinning)
- every patient is given a leaflet on DVT pre-admission clinic

10

How does protein C activation occur and what does it do?

stops clot propagating but you need an intact endothelium
- protein c is activated by thrombin-thrombomodulin complex
- activation protein c binds free protein s which then inactivates activated FV and FVIII

11

Which FV is slight resistance to activated protein c?

FV leiden

12

Which SNPs predict risk of VTE recurrence?

F5 FV leiden = non-penetrant
F2 20210 G>A
ABO
FGG 10034 C>T
FXI

Low GRS (<1risk allele) = 9.4% recurrence at 6 years
high GRS (>5 risk alleles) = 20.3% recurrence at 6 years

13

Why do VTEs arise?

from a combination of interacting genetic and acquired risk factors
with increasing age your risk increases