Thrombosis, Embolism, Infarction and Ischaemia

Question 1

What is Virchow’s Triad?

Answer 1

3 categories of factors which contribute to formation of thrombosis:
- Vessel wall (Trauma/surgery, atherosclerosis)
- Blood flow (AF, varicose veins),
- Blood composition (changes in malignancy, pregnancy, oestrogen therapy, sepsis)

Question 2

What is the histopathology of arterial and venous thrombus?

Answer 2

Arterial - Many platelets and only small amounts of fibrin (white)
Venous - Many fibrin with trapped red cells (red)

Question 3

What are the differential diagnosis of a sore leg?

Answer 3

Trauma - Freactures, dislocations, muscle strain/rupture
MSK - Arthritis (Osteo, rhumatoid, septic), gout and psudogout, bakers cyst, tenosynovitis, bursitis, myopathies.
Skin/soft tissue infections
Vascular - Venous occlusion (DVT,) arterial occlusion (PAD, cardiac thromboemboli) or lymphoedema.

Question 4

What are the causes of bilateral leg oedema?

Answer 4

Usual systemic oedema caused by heart failure, cirrhosis, nephrotic syndrome, malnutrition or immobility

Question 5

What are the risks for a DVT

Answer 5

Vessel wall - Increasing age, varicose veins or surgery.
Blood flow - Obesity, pregnancy, immobilisation, IV catheters.
Composition of blood - Thrombophilia’s, inflammatory conditions, oestrogen hormones

Question 6

How is the diagnosis of DVT made?

Answer 6

• Clinical history and examination,
• Blood tests (D-dimer - not very specific)
• Image venous system of legs using compression ultrasound (Doppler)
• Well’s score

Question 7

What are some of the potential outcomes following a DVT?

Answer 7

• Painful, swollen leg,
• PE,
• Recurrent VTE,
• Venous insufficiency,
• Post thombotic syndrome which can lead to ulceration

Question 8

What are some of the potential outcomes following a PE?

Answer 8

• Dyspnoea, chest pain, haemoptysis,
• Collapse,
• Death,
• Recurrent VTE,
• Chronic thomoembolic pulmonary hypertension

Question 9

What is the treatment of a DVT

Answer 9

• Prevent thrombus extending or embolising via anticoagulant therapy (Heparin, warfarin or DOAC)
• Remove risk factors (eg oestrogen)
• Pain relief
• Graduated elastic compression stockings

Question 10

Explain the formation of an atheroma

Answer 10

• Damage in endothelium (due to hypertension, smoking, hyperglycaemia) causes LDL deposition (inflammation) in the tunica intimat. Monocytes migrate into the tunica intima and become macrophages and phagocytose the oxidised LDL. This causes them to become foam cells. Foam cells die locally and produce apoptotic bodies. Atheroma develops

Question 11

What are the risk factors for atherosclerotic disease?

Answer 11

Smoking, hypertension, hyperlipidaemia, diabetes, obesity, family history

Question 12

What is the treatment of acute coronary syndrome?

Answer 12

• Prevent thrombus extension (Anti-platelet and anticoagulant)
• Remove thrombus (thrombolysis via alteplase or PCI)
• Widney the stenotic plaque (balloon angioplasty or insertion of stent)
• Prevent further thrombus (antiplatelet and statin)

Question 13

What are the complications following an MI

Answer 13

• Death,
• Arrhythmia,
• Pericarditis,
• Myocardial rupture,
• Mitral valve prolapse,
• Left ventricular aneurysm +/- thrombus
• Heart failure

Question 14

What are some differentials for limb weakness

Answer 14

MSK - Myopathy and arthropathy.
Neuro - Peripheral neuropathy, spinal lesion, cerebral lesion

Question 15

What is the treatment for stroke in AF?

Answer 15

• Remove thrombus (rare) via thrombolysis or carotid end-arterectomy.
• Treat AF with anticoagulant, rate or rhythm control and replace any defective heart valve.
• Treat hypertension/hypercholesterolaemia