Cardiovascular Flashcards
Where can thrombosis occur?
Thrombosis can occur in:
Arterial circulation: high pressure - platelet rich
Venous circulation: low pressure - fibrin rich
What is the normal bleeding time?
2-7 minutes
List a symptom that could occur due to an arterial thrombosis in the coronary circulation?
- Angina
- Shoulder pain
- Sudden death
List a symptom that could occur due to an arterial thrombosis in the cerebral circulation?
- Headache
- Slurred speech
- Unilateral weakness
- CVA cerebral vascular accident
List a symptom that could occur due to an arterial thrombosis in the peripheral circulation?
- Pain in leg
- Stomach-ache
What is the underlying cause of arterial thrombosis in majority of cases?
When an artery is damaged by atherosclerosis
List some examples of Arterial thrombosis Aetiology
Atherosclerosis
Inflammatory
Infective
Trauma
Tumours
What is the treatment for coronary arterial thrombosis?
- Aspirin.
- LMWH or Fondaparinux or UFH
- Thrombolytic therapy
- Reperfusion
What is the treatment for cerebral arterial thrombosis?
- Aspirin, other anti-platelets
- Thrombolysis
- Catheter directed treatments
Reperfusion
Why is heparin not used in patients who have had a CVA (cerebral vascular accident)
Increased risk of bleeding complications
What is the treatment for arterial thrombosis in other sites?
- Antiplatelets, statins
- Role of anticoagulants evolving
- Endovascular vs Surgical
Why is Fondaparinux used instead of heparin?
Much higher risk of bleeding when using heparin.
Fondaparinux also has a longer half life.
Where does venous thrombosis occur?
*Peripheral - such as the ileofemoral, femoro-popliteal
- Other sites such as cerebral and visceral
What are the symptoms of DVT?
Usually non-specific symptoms, pain and swelling, groin strain. Calf pain, chest pain, and breathlessness is a common clinical scenario however.
Briefly describe the investigations might be done in order to diagnose a DVT.
- D-dimer; looks for fibrin breakdown products. If normal, you can exclude DVT. Abnormal does not confirm diagnosis however.
- Ultrasound compression scan; if you can’t squash the vein = clot.
What is the treatment for DVT?
- Heparin or LMWH.
- Oral warfarin or DOAC.
- Endo-vascular treatment
Give 5 risk factors for DVT.
- Surgery, immobility, leg fracture.
- OCP, HRT.
- Long haul flights.
- Genetic predisposition: Factor 5 Leiden
- Pregnancy.
Causes of thrombosis (Virchow’s triangle, typically 2 out of these 3)
- Hypercoagulability
- Venous stasis
- Endothelial damage
When would the treatment of DVT be more aggressive?
when the DVT are really long ie right to the IVC from the leg, and when patients are really symptomatic.
Prevention of DVT
- Mechanical or chemical thromboprophylaxis
- Compression socks
- Also early mobilisation and good hydration
What is heparin?
- Heparin is an anticoagulant
- It activates antithrombin which then inhibits thrombin and factor Xa.
- It has a short half-life
How is unfractionated heparin administered? (UFH)
Intravenously, continuous infusion
How is low molecular weight heparin administered? (LMWH). What is it used for?
Once daily, weight-adjusted dose given subcutaneously. Used for treatment and prophylaxsis
Is HIT (Heparin induced thrombocytopenia) more common after LMWH or UFH?
UFH