Aortic disease Flashcards
Sinuses of valsalva
3 pouches that sit above the aortic valve in a garlic bulb shape. the left and right contain the left and right coronary ostiums. The sinotubular junction is right above them.
Basic Histology of the aorta
Tunica intima
Layer of endothelial cells
Subendothelial layer – collagen and elastic fibres
Separated from tunica media internal elastic membrane.
Tunica media
smooth muscle cells
secrete elastin in the form of sheets, or lamellae
Tunica adventitia
Thin connective tissue layer
Collagen fibres and elastic fibres (not lamellae)
The collagen in the adventitia prevents elastic arteries from stretching beyond their physiological limits during systole
Classification of Aneurysms By Type
Saccular - bulges on onse side
Fusiform - bulges on both sides
False aneurysm - only an aneurysm in one layer of tunica
dissecting aneurysm - blood is going into gap between layers
True Aneurysm and associations
Weakness & dilation of wall Involves all 3 layers Associated with Hypertension Atherosclerosis Smoking Collagen abnormalities (Marfan’s, cystic medial necrosis) Trauma Infection (mycotic/syphillis)
False Aneurysm and associations
Rupture of wall of aorta with the haematoma either contained by the thin adventitial layer or by the surrounding soft tissue
.Inflammation ( eg endocarditis with septic emboli)
Trauma
Iatrogenic
Thrill
Bruit
Pulsatile mass
Ischaemia
Rupture
Classification of aortic aneurysm by site
ascending, arch, descending, abdominal
Signs and Symptoms of Thoracic Aneurysms
Asymptomatic
Based on the location of the aneurysm.
shortness of breath or even heart failure (AR)
dysphagia and hoarseness (ascending aorta, chronic)
Sharp chest pain radiating to back –between shoulder blades –Possible dissection!
Pulsatile mass
Hypotension
Aortic Dissection
Tear in the inner wall of aorta
Blood forces walls apart
Acute –medical/surgical emergency
Chronic
false lumen can progress in an antegrade or retrograde direction
May occlude branches (eg mesenteric, carotid, renal, spinal)
Rupture - back into the lumen or externally in to pericardium (tamponade) or mediastinum
Dilation of ascending aorta may cause acute aortic regurgitation
Stanford classification
Type A- involves ascending aorta
Type B- does not involve ascending aorta
DeBakey classification
Type I- originates in ascending aorta, propagates at least to arch, often beyond it distally
Type II- originates in and is confined to ascending aorta
Type III- originates in descending aorta and extends distally down aorta or rarely retrograde into the arch and ascending aorta
Aetiological factors of dissection
Hypertension
Atherosclerosis
Trauma
Marfan’s syndrome
Histology of dissection
cystic medial necrosis
Symptoms and Signs of Aortic Dissection
Tearing, severe chest pain (radiating to back)
Collapse (tamponade, acute AR, external rupture)
Beware inferior ST elevation
~50% mortality pre-hospital
Reduced or absent peripheral pulses (BP mismatch between sides)
Hypotension/ hypertension
Soft early diastolic murmur (AR)
Pulmonary oedema
Chest x-ray usually shows a widened mediastinum
Diagnosis can be confirmed by echocardiogram or CT scanning
Treatment of dissection
Type A-Surgery
Type B -Meticulous blood pressure control
-Sodium nitroprusside plus beta blocker
Infection and Inflammation of aorta
Infection: Syphyllis
Inflammation: Takayasu’s Arteritis
Takayasu’s Arteritis
Granulomatous vasculitis Females>Males Aorta & main branches Stenosis, thrombosis, aneurysms, renal artery stenosis, neurological sx Steroids Surgery
Syphilis
STD
Treponema pallidum
Antibiotics prevent late stages.
Primary - chancre ( bulge on penis) Secondary - rash Tertiary - Without treatment – 1/3rd develop 1 of 3 types Late neuro-syphillis Gummatous syphillis Cardiac syphillis
Cardiac syphillis (10-30yrs post infection)
Syphilitic aortitis – aneurysm
Aortic regurgitation
Congenital aortic aneurysm causes
Bicuspid Aortic Valve
Marfan’s Syndrome
Coarctation
Bicuspid Aortic Valve
Most common congenital abnormality
1-2% prevalence
Prone to stenosis +/- regurgitation
Associated with coarctation
Abnormal aorta (reduced tensile strength)
Prone to aneurysm/ dissection
Monitor with echo/ MRI
Coarctation
Aortic narrowing close to where
Ductus arteriosus inserts
(ligamentum arteriosum)
3 types:
Pre-ductal (5% turner’s) can be life-threatening if severe narrowing (B)
Ductal (A)
Post-ductal (C) –most common in adults – hypertension in upper extremities, weak pulses in lower limbs
Associated with rib-notching (collateral circulation)
Signs 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 radio-femoral delay
Symptoms of coarctation
Infancy (severe)
Heart failure
Failure to thrive
Later life
Hypertension
Marfan’s Syndrome
Aneurysm Dissection Fibrillin 1 gene Connective tissue weakness Aortic/ Mitral valve prolapse – regurgitation Skeletal system Eyes (cataract, lens dislocation) Vascular – aneurysm, dissection Lungs (pneumothorax)
