Ischaemic Heart & Vascular Disease Flashcards
Define ischaemia
Ischaemia is the result of impaired vascular perfusion depriving the affected tissue of nutrients (inc. O2). Can be reversible depending on multiple factors including speed of onset, local demand and duration.
Define infarction
Infarction refers to ischaemic necrosis (death) of a tissue or organ secondary to occlusion/reduction of the arterial supply or venous drainage. Recovery will depend on a tissue’s regenerative ability.
Define haemostasis
Haemostasis a set of well-regulated processes that accomplish two important functions; 1 – maintain blood in a fluid, clot free state in normal vessels; 2 – induce rapid, localised haemostatic plug at site of vascular injury.
Define thrombosis and thrombus.
Thrombosis is the formation of a solid or semi-solid mass from the constituents of blood, within the vascular system, during life. Resulting mass = thrombus. If it occurs post mortem, it is a clot not a haemorrhage.
Define embolism
Embolism refers to any detached intravascular solid, liquid or gaseous mass which is carried by the bloodstream to a site distant from the point of origin.
Most (>99%) of emboli are fragments of detached clot, i.e. thromboemboli.
What does post thrombotic syndrome occur after?
What is it characterized by?
Occurs in 1/3 of patients post idiopathic DVT. Characterized by: - Pain - Oedema - Hyperpigemtation - Eczema - Varicose collateral veins - Venous ulceration - Iron leeching out of the blood (looks yellowy)
Chronic thromboembolic pulmonary hypertension
What is it a complication of?
What happens?
Rare but serious complication of PE.
The original embolic material is replaced over time with fibrous tissue that is incorporated into the intima and media of the pulmonary arteries.
This leads to increased pulmonary resistance, and ultimately right heart failure.
What are two non-invasive investigation of claudication?
- Ambultaory blood pressure index - measure the ankle pressure over brachial pressure over a period of exercise.
- Duplex ultrasound scanning - colour mismatch shows turbulence due to narrowing.
What does guardian therapy for lower limb ischaemia include?
Slowing progression:
- Smoking
- Lipid lowering
- Antiplatelets
- Hypertension Rx
- Diabetes Rx
- Lifestyle issues
What is Endarterectomy and what is it used for?
Surgical removal of part of the inner lining of an artery, together with any obstructive deposits, most often carried out on the carotid artery or n vessels supplying the legs when they are blocked.
Which two branches of the thoracic aorta do the renal arteries lie between?
Superior mesenteric and inferior mesenteric.
What is the definition of aneurysm?
An artery with a dilatation >50% of its original diameter
What is the difference between a true and a false aneurysm?
True = vessel wall is intact False = there is a breach in vessel wall, resulting in a collection of blood in the outer layer (adventitia)
What are the three types of aneurysm?
- Saccular - forms a little blob off of the artery
- Fusiform - general widening of the artery
- Mycotic - arises secondary to an infectious process, involving all three layers of the artery
What is the brief pathogenesis of aneurysm formation?
Medial degeneration Disruption of the regulation of elastic/collagen in aortic wall Aneurysmal dilatation Increase in aortic wall stress Progressive dilatation (Law of LaPlace ATHEROSCLEROSIS IS INCIDENTAL
