Aortic dissection Flashcards
Define
Tear in the tunica intima leading to the formation of a false lumen between the intima and media, where blood accumulates
Epidemiology
Men
Over the age of 50
Aetiology
Hypertension Bicuspid aortic valve Connective tissue disorders e.g. Marfan's, EDS Atherosclerosis Smoking FH Cocaine/amphetamine use Untreated coarctation
Pathophysiology
High shear tension against the tunica intima
In HTN: hyaline arteriolosclerosis (build up of proteins around the wall) of the vasa vasorum (the small vessels around a vessel) around the aorta can cause ischaemia/malnutrition of the tunica media, thus leading to weakness and the development of dissection.
Symptoms
Shearing/ripping/tearing central chest pain
Radiates to upper back between scapula
Sometimes even down arm and to jaw
Signs
- Marfan-like signs (arachnodactyly, high arched palate, tall stature, hypermobile joints, pectus excavatum)
- EDS-like signs (easy bruising, hypermobility of small joints, premature ageing of skin)
- Differences in blood pressure and pulse between arms and between lower and upper extremities
- Diastolic crescendo murmur (due to aortic regurgitation if the blood hits against the valves)
Note: 20% of patients present with syncope and no pain!
Hypotension
Compromised limb/organ perfusion:
- paraplegia
- abdo pain
- hemiparesis
- altered mental state
Decreased breath sounds on left side:
- pleural effusion
What would radiation to the lower back suggest?
Descending aorta dissection
Anterior chest pain is associated with?
Ascending aorta dissection
What is hypotension suggestive of?
Cardiac tamponade (when blood pools between the covering of the heart and the heart itself, as a result of bleeding through the tunica adventitia)
Investigations
ECG - to rule out MI CXR - widened mediastinum CT angiography from chest to pelvis Echo - check for aortic regurg Cardiac enzymes - rule out MI (12 hrs later)
Bloods:
- elevated creatinine:urea
- elevated AST and ALT
- elevated or normal lactate
- low FBC if anaemia or haemorrhage
Blood type and cross match if transfusion/surgery indicated
Classification
Stanford Type A - Ascending aorta
Stanford Type B - everything else
If you think it’s aortic dissection, how would you investigate? What would you be looking for?
ECG (but be careful, because it might show MI that is actually post dissection)
CXR - widened mediastinum
Raised leucocytosis, Cr, Trops and D-dimer raised
CROSS MATCH BLOOD for these patients
Echocardiogram (Transthoracic or transoesophageal (TOE))
CT aortagram (GOLD STANDARD)
Classify aortic dissection and the symptoms
Type A - Ascending aorta,
Type B - Descending aorta
Where is the murmur?
On back, at the left scapula
Complications
Tamponade
What might you see on a CXR?
Widened mediastinum
Give three things that can complicate dissection
Aortic regurgitation
MI
Pleural effusion
FH of sudden death might suggest a particular connective tissue disease. What is this and what is the mode of inheritance?
Marfan’s - autosomal dominant pattern of inheritance
Key features of marfans
Lens dislocation
Arachnodactyly
High arched palate
Immediate management of aortic dissection
IV antihypertensives
Oxygen
Consequences
Rupture
Vessel branch occlusion
Aortic regurg
Pericardial effusion /tamponade
Risk factors for aortic dissection
Marfan's/EDS HTN Cardio surgery/PCI Infection e.g. syphilis or vasculitis artertitis (Takasayu's giant cell disease) Crack cocaine
Differentiate between MI and AD
Maximal pain at onset, unlike MI which gets worse with time
Symptoms?
look back at recording with omid 13.01.2021
Management
ABCD Call cardiothoracic surgeonand ITU O2 Wide bore IV access Warn blood bank
Note: thin blood could preciptate worsening of the false lumen, so you need to take them off anticoags etc I think
Control HR and BP
IV labetalol combined with vasodilators e.g. GTN
Note: Start beta blocker first to avoid increased aortic wall stress from reflex tachy
Indications for surgery
Type A
Branch occlusion
Leak
