Week 3 - Aortic Disease Flashcards
What does aortic disease include?
Aneurysm, aortic dissection, atherosclerosis
What are the 4 parts of the aorta?
- aortic root - aortic valve to sinotubular junction
- ascending thoracic aorta - sinotubular jnction to brachiocephalic artery
- aortic arch - brachiocephalic artery to left subclavian artery
- descending thoracic aorta - left subclavian artery to diaphragm
What are the sections of the aortic root?
has right, left and and non-coronary sinus of valsalva. correspond to a cusp of the aortic valve - right coronary cusp, left coronary cusp, non-coronary cusp
What is the histology of the aorta?
T. intima is endothelial cells with collagen and elastic fibres, separated from t.media by thin elastic membrane
T.media is smooth muscle which secrete elastin sheets
T. Adventitia is a thin connective tissue layer - collagen and elastic fibres - collagen prevents over stretch
What are risk factors of atherosclerosis?
hypertension, smoking, hypercholesterolaemia, diabetes, family history
What is an aneurysm?
enlargement of artery caused by weakening of vessel wall
What are the types of aneurysm?
true aneurysm:
saccular - enlarged on one side
fusiform - enlarged on both sides
false aneurysm:
enlargement due to rupture in artery wall. blood is contained in either thin t.adventita layer, or external surrounding structures
What are common causes of true aneurysm?
- hypertension,
- bicuspid aortic valve,
- collagen abnormalities,
- infection and trauma
What are common causes of false aneurysm?
trauma, iatrogenic or inflammation
What are the symptoms of an aortic aneurysm?
- depends on size and location.
- in aortic regurgitation, patient may have SoB or heart failure.
- it may compress other areas, causing dysphasia, hoarse voice, back pain
What investigations can be carried out to diagnose aneurysm?
- CXR shows widened mediastinum.
- CT and MRI used to diagnose.
- echocardiogram shows root but not other parts of aorta
What is the test of choice for aortic aneurysm?
CT and MRI
What is an aortic dissection?
tear in intima of aorta, blood enters causing split in media.
What is the cause of an aortic dissection?
same as aneurysm - hypertension, atherosclerosis, bicuspid aortic valve, trauma
What do you find histologically in an aorta that causes an aortic dissection to occur?
cystic medial necrosis. cysts replace smooth muscle and elastic fibres in media, weakening it so tear is more likely to occur
What are the symptoms of aortic dissection?
propagation of blood may occlude any of the main arteries - carotid, coronary, renal, etc. symptoms depend on this
What classification system is there for aortic dissection?
stanford system.
A is any dissection involving ascending aorta
B is any dissection not involving ascending aorta
What is the clinical presentation of aortic dissection?
- severe sharp chest pain radiating to back,
- collapse due to heart issues,
- stroke due to involvement of carotid arteries
What is found on examination of aortic dissection?
- absent or reduced peripheral pulse,
- changed blood pressure,
- BP mismatch between limbs,
- aortic regurgitation murmur,
- signs of stroke if involving carotid
What investigations are carried out for aortic dissection?
- CT angiogram aorta IS BEST - confirms diagnosis
- ECG to see if there’s coronary involvement
- CXR for widened mediastinum
- echocardiogram shows aortic root but nothing else
What is the mortality rate of aortic dissection?
VERY HIGH! 50% die before hospital and many die after
how do you treat aortic dissection?
depends on type
type A - control BP then go for emergency surgery
type B - control blood pressure and assess risk of rupture and involvement of branches of aorta. if so consider percutaneous
What is takayasu’s arteritis?
granulomatous condition which affects aorta. may cause stenosis, thrombus, aneurysm. may need treatment
What is syphilis?
STI which may cause aortic aneurysm or regurgitation in late stages
What conditions predispose aortic aneurysm?
- aortic bicuspid valve,
- coarctation,
- marfan syndrome
What is marfan syndrome?
connective tissue weakness causing proneness to aortic regurgitation, aortic dissection and aneurysm
What is a false aneurysm?
A false aneurysm involves a collection of blood/haematoma which is either contained by the adventitial layer or the surrounding tissue
What is notching of ribs a common sign of?
seen on xray. coarctation of aorta. causes enlargement of intercostal arteries
