Aortic Disease Flashcards
What is the basic histology of the tunica intima?
Layer of endothelial cells
Subendothelial layer - collagen and elastic fibres
Separated from the tunica media by internal elastic membrane
What is the basic histology of the tunica media?
Smooth muscle cells
Secrete elastin in the form of sheets or lamellae
What is the basic histology of the tunica adventitia?
Thin connective tissue layer
Colagen fibres and elastic fibres
The collagen in the adventitia prevents elastic arteries from stretching beyond their physiological limits during systole
When does atherosclerosis begin?
In early childhood
What are the risk factors for atherosclerosis?
Hypertension Hypercholesterolaemia Smoking Diabetes Family history Male
What are the possible outcomes of atherosclerosis?
Stroke
MI (ischaemia and infarction)
Aneurysm
What is an aneurysm?
A localised enlargement of an artery caused by a weakening of the vessel wall
What are the features of a true aneurysm?
Weakness and dilatation of the wall involving all 3 layers
Associated with hypertension, atherosclerosis, smoking and collagen abnormalities
Also associated with trauma and infection
What are the features of a false aneurysm
Rupture of the wall of the aorta with the haematoma either contained by the thin adventitial layer or by the surrounding soft tissue Inflammation Thrill Bruit Pulsatile mass Ischaemia Rupture
What are the signs and symptoms of thoracic aneurysms?
Asymptomatic
Based on location of the aneurysm
Dyspnoea or heart failure
Dysphagia and hoarseness
Sharp chest pain, radiating to back/between shoulder blades
Pulsatile mass felt on abdominal examination
Hypotension
What is an aortic dissection?
Tear in the inner wall of the aorta
Blood forces the walls apart
Acute is a medical emergency
What are the aetiological factors that cause aortic dissection?
Hypertension
Atherosclerosis
Trauma
Marfan syndrome
What is seen on histology of a patient with aortic dissection?
Cystic medial necrosis - loss of elastin and muscle fibres in the media with accumulation of mucopolysaccharides in cyst-like spaces
What directions can false lumens progress in?
Antegrade or retrograde
Where might an aortic dissection rupture?
Back into the lumen or externally into the pericardium or mediastinum
What might dilatation of the ascending aorta cause?
Acute aortic regurgitation
What is the DeBakey type I aortic dissection?
Originates in the ascending aorta and propagates at least to the aortic arch and often beyond it distally
What is the DeBakey type II aortic dissection?
Originates in and is confined to the ascending aorta
What is the DeBakey type III aortic dissection?
Originates in the descending aorta and extends distally down the aorta or rarely retrograde into the aortic arch and ascending aorta
What is the Stanford type A aortic dissection?
All dissections involving the ascending aorta, regardless of the site of origin
What is the Stanford type B aortic dissection?
All dissections not involving the ascending aorta
What are the symptoms and signs of aortic dissection?
Tearing, severe chest pain radiating to the back
Collapse - tamponade, acute rupture, external rupture
Inferior ST elevation
What is the mortality of aortic dissection pre-hospital?
Around 50%
What might be seen on examination of a patient with aortic dissection?
Reduced or absent peripheral pulses, BP mismatch between sides Hypotension/hypertension Soft early diastolic murmur Pulmonary oedema CXR usually shows widened mediastinum
What can confirm a diagnosis of aortic dissection?
Echo or CT
What is the investigation of aortic aneurysm and aortic dissection?
Echo
CT
CXR
What are the treatments of aortic aneurysm and aortic dissections?
Surgery
Meticulous blood pressure control
Sodium nitroprusside plus a beta blocker
What is Takayasu’s arteritis?
Granulomatous vasculitis of the aorta and main branches
What sex is affected more by Takayasu’s arteritis?
Females
What are the features of Takayasu’s arteritis?
Stenosis Thrombosis Aneurysm Renal artery stenosis Neurological symptoms
What are the treatment options for Takayasu’s arteritis?
Steroids
Surgery
What is the causative organism of syphilis?
Treponema pallidum
What is the presentation of a primary syphilis infection?
Chancre
Without treatment of a primary syphilis infection, what types of tertiary syphilis can develop?
Late neuro-syphilis
Gummatous syphilis
Cardiac syphilis
When does cardiac syphilis present?
10-30 years post-infection
What cardiovascular conditions can tertiary syphilis result in?
Syphilitic aortitis - aneurysm
Aortic regurgitation
What are the causes of congenital aortic aneurysm?
Bicuspid aortic valve
Marfan syndrome
Coarctation
What is the prevalence of bicuspid aortic valve?
1-2%
What are patients with a bicuspid aortic valve prone to?
Stenosis
Regurgitation
Aneurysm
Dissection
What is biscupid aortic valve associated with?
Coarctation
What is the effect of a bicuspid aortic valve on the abdominal aorta?
Reduced tensile strength
How can a bicuspid aortic valve be monitored?
Echo
MRI
Where are the 3 shunts involved in coarctation of the aorta?
Ductus arteriosus
Foramen ovale
Ductus venosus
What are the types of coarctation?
Pre-ductal
Ductal
Post-ductal
What are the features of post-ductal coarctation?
Most common in adults
Hypertension in upper extremities
Weak pulses in lower limbs
Associated with rib notching
What are the signs and symptoms of coarctation?
Cold legs
Poor leg pulses
If before left subclavian artery - radial-radial and right radial-femoral delay
If after left subclavian artery - no radial-radial delay, right and left radial-femoral delay
Heart failure
Failure to thrive in infancy
Hypertension in later life
What imaging can be done to diagnose coarctation?
CXR
CMRI
What are the features of Marfan syndrome?
Mutation of fibrillin 1 gene
Connective tissue disorder
Aortic or mitral valve prolapse, regurgitation
Skeletal system involvement
Eye involvement - cataract, lens dislocation
Vascular - aneurysm, dissection
Lungs - pneumothorax
