Diseases of the Thoracic Aorta Flashcards Preview

Cardiovascular System > Diseases of the Thoracic Aorta > Flashcards

Flashcards in Diseases of the Thoracic Aorta Deck (37)
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1
Q

Features of Tunica Intima

A
  • Layer of endothelial cells
  • Subendothelial layer: collagen and elastic fibres
  • Separated from tunica media internal elastic membrane
2
Q

Features of Tunica media

A
  • Smooth muscle cells

- Secrete elastin in the form of sheets, or lamellae

3
Q

Features of Tunica adventitia

A
  • 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
4
Q

What are risk factors of atherosclerosis?

A
  • Hypertension
  • Hypercholesterolaemia
  • Smoking
  • Diabetes
  • Family history
  • Male > Female (relative protection in females until menopause)
5
Q

Atherosclerosis timeline

A

Foam cells > Fatty streak > Intermediate lesion > Atheroma > Fibrous plaque > Complicated lesion/Rupture

6
Q

What can atherosclerosis lead to?

A
  • Stroke
  • Myocardial infarction
  • Aneurysm
7
Q

What is an Aneurysm?

A

A localised enlargement of an artery caused by a weakening of the vessel wall

8
Q

Classification of aneurysms by type

A
  • Saccular aneurysm
  • Fusiform aneurysm
  • False aneurysm
  • Dissecting aneurysm

Saccular and Fusiform are true aneurysms

9
Q

What are features of a True aneurysm?

A
  • Weakness & dilation of wall

- Involves all 3 layers

10
Q

What are true aneurysms associated with?

A
  • Hypertension
  • Atherosclerosis
  • Smoking
  • Collagen abnormalities (Marfans’s, cystic medial necrosis)
  • Trauma
  • Infection (mycotic/syphillis)
11
Q

What is a False Aneurysm?

A

Rupture of wall of aorta with the haemotoma either contained by the thin adventitial layer or by the surrounding soft tissue

12
Q

What does a False aneurysm cause?

A
  • Inflammation (e.g. endocarditis with septic emboli)
  • Trauma
  • Iatrogenic
  • Thrills
  • Bruit
  • Pulsatile mass
  • Ischaemia
  • Rupture
13
Q

Classification of aortic aneurysm by site

A
  • Normal
  • Ascending aorta aneurysm
  • Aortic arch aneurysm
  • Descending aorta aneurysm
  • Abdominal aorta aneurysm
14
Q

Signs and symptoms of Thoracic aneurysms

A

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
15
Q

Features of aortic dissection

A
  • Tear in the inner wall of aorta
  • Blood forces walls apart
  • Acute - medical/surgical emergency
  • Chronic
16
Q

Classification systems of thoracic aortic dissection

A

DeBakey

  • Type I
  • Type II
  • Type III

Stanford

  • Type A: all dissections involving the ascending aorta, regardless of the site of origin.
  • Type B: All dissections not involving the ascending aorta.
17
Q

Features of Dissection

A
  • False lumen can progress in an antegrade or retrograde direction
  • May occlude branches (e.g. 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 regurgutation.
18
Q

Aetiological factors of dissection

A
  • Hypertension
  • Atherosclerosis
  • Trauma
  • Marfan’s syndrome
19
Q

Histology of dissection

A

Cystic medial necrosis

20
Q

Symptoms of aortic dissection

A
  • Tearing, severe chest pain (radiating to back)
  • Collapse (tamponade, acute AR, external rupture)
  • Beware inferior ST elevation
21
Q

Examination signs of aortic dissection

A
  • Reduced or absent peripheral pulses (BP mismatch between sides)
  • Hypotension/hypertension
  • Soft early diastolic mumur (AR)
  • Pulmonary oedema
  • Chest X-ray usually shows a widened mediastinum
  • Diagnosis can be confirmed by echocardiogram or CT scanning
22
Q

What is the treatment for Type A aortic dissection?

A

Surgery: prophylactic aortic root surgery

23
Q

What is the treatment for Type B aortic dissection?

A
  • Meticulous blood pressure control

- Sodium nitroprusside plus beta blocker

24
Q

Infection and Inflammation affecting the aorta

A

Infection: Syphyllis

Inflammation: Takayasu’s Arteritis

25
Q

Features of Takayasu’s Arteritis

A
  • Granulomatous vasculitis
  • Females > Males
  • Aorta & main branches
  • Stenosis, thrombosis, aneurysms, renal artery stenosis, neurological sx
  • Steroids
  • Surgery
26
Q

Features of Syphilis

A
  • STD
  • Treponema pallidum
  • Antibiotics prevent late stages
27
Q

Signs of Primary and Secondary syphillis

A

Primary - Chancre

Secondary - Rashes (mainly back rashes)

28
Q

Tertiary Syphilis without treatment

A
  • Late neuro-syphillis
  • Gummatous syphillis
  • Cardiac syphillis
29
Q

Features of congenital aortic aneurysm

A
  • Bicuspid aortic valve
  • Marfan’s syndrome
  • Coarctation
30
Q

Features of Bicuspid aortic valve

A
  • 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
31
Q

What occurs during Aortic Coarctation?

A

Narrowing below the left subclavian artery

32
Q

What are the 3 shunts in coarctation?

A
  • Ductus arteriosus
  • Foramen ovale
  • Ductus venosus
33
Q

Features of Coarctation

A
  • Aortic narrowing close to where Ductus arteriosus inserts (ligamentum arteriosum)

3 Types:

  • Pre-ductal: (5% turner’s) can be life-threatening if severe narrowing
  • Ductal
  • Post-ductal: most common in adults, hypertension in upper extremities, weak pulses in lower limbs
34
Q

Signs of Coarctation

A
  • 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
35
Q

Symptoms of coarctation

A

Infancy (severe)

  • Heart failure
  • Failure to thrive

Later life
- Hypertension

36
Q

Imaging for coarctation

A
  • Chest Xray

- CMRI: narrowing distal to the subclvian artery

37
Q

Features of Marfan’s Syndrome

A
  • Fibrillin 1 gene
  • Connective tissue weakness
  • Aortic/Mitral valve prolapse - regurgitation
  • Skeletal system
  • Eyes (cataract, lens dislocation)
  • Vascular: aneurysm, dissection
  • Lungs (pneumothorax)
  • Aneurysm
  • Dissection