Aortic Dissection

Question 1

Aortic dissection is rare

Answer 1

true

Question 2

Describe the pathophysiology of aortic dissection

Answer 2

tear in the tunica intima of the wall of the aorta

Question 3

Which syndromes are associated with aortic dissection?

Answer 3

Turner’s and Noonan’s syndrome

collagens: Marfan’s syndrome, Ehlers-Danlos syndrome

Question 4

Which infection is associated with aortic dissection?

Answer 4

syphilis

Question 5

What is the most important risk factor re aortic dissection?

Answer 5

Hypertension

Question 6

Can pregnancy be associated with aortic dissection

Answer 6

yes

Question 7

Which valve deformity is associated with aortic dissection

Answer 7

bicuspid aortic valve

Question 8

Describe the characterstic chest pain associated with aortic dissection?

Answer 8

typically severe, radiates through to the back and ‘tearing’ in nature

Question 9

What will the pulse be like in aortic dissection?

Answer 9

weak or absent carotid, brachial, or femoral pulse

variation (>20 mmHg) in systolic blood pressure between the arms

Question 10

Which murmur would you hear in aortic dissection?

Answer 10

aortic regurgitation

Question 11

Describe how symptoms would manifest if the coronary arteries were involved

Answer 11

angina

Question 12

Describe how symptoms would manifest if the spinal arteries were involved

Answer 12

paraplegia

Question 13

Describe how symptoms would manifest if the distal aorta was involved

Answer 13

limb ischaemia

Question 14

What ECG changes would you see in aortic dissection

Answer 14

the majority of patients have no or non-specific ECG changes.
In a minority of patients, ST-segment elevation may be seen in the inferior leads

Question 15

What two classifications are used for aortic dissection?

Answer 15

Stanford classification

DeBakey classification

Question 16

Describe the Stanford classification Type A & Type B

Answer 16

type A - ascending aorta, 2/3 of cases

type B - descending aorta, distal to left subclavian origin, 1/3 of cases

Question 17

Describe the Debakey Classification

Answer 17

type I - originates in ascending aorta, propagates to at least the aortic arch and possibly beyond it distally
type II - originates in and is confined to the ascending aorta
type III - originates in descending aorta, rarely extends proximally but will extend distally

Question 18

What is the investigation of choice for aortic dissection?

Answer 18

CT angiography of the chest, abdomen and pelvis

Question 19

Is CT angiography better for stable or unstable patients?

Answer 19

suitable for stable patients and for planning surgery

Question 20

What will you see on CT angiography?

Answer 20

a false lumen is a key finding in diagnosing aortic dissection

Question 21

What would you see on CXR?

Answer 21

widened mediastinum

Question 22

Transoesophageal echocardiography (TOE) is suitable for which patients?

Answer 22

more suitable for unstable patients who are too risky to take to CT scanner

It’s important to remember that patients may present acutely and be clinically unstable.

Question 23

What classification determines management?

Answer 23

Stanford classification Type A & Type B

Question 24

How do you manage a Type A dissection?

Answer 24

surgical management,

but blood pressure should be controlled to a target systolic of 100-120 mmHg whilst awaiting intervention

Question 25

How do you manage a Type B dissection?

Answer 25

conservative management
bed rest
reduce blood pressure IV labetalol to prevent progression

Question 26

Complications of backward tear?

Answer 26

aortic incompetence/regurgitation

MI: inferior pattern is often seen due to right coronary involvement

Question 27

Complications of a forward tear?

Answer 27

unequal arm pulses and BP
stroke
renal failure

Question 28

Why might focal neurological defects present with aoritc dissection?

Answer 28

propagation of the intimal tear to branch arteries

due to mass effects as the expanding aorta compresses surrounding structures

Question 29

compression of the sympathetic trunk by the expanding aortic dissection would result in what?

Answer 29

Horner’s syndrome (classically ptosis, miosis and anhidrosis)

Question 30

A 52-year-old male presents with tearing central chest pain. On examination he has an aortic regurgitation murmur. An ECG shows ST elevation in leads II, III and aVF. What is the diagnosis?

Answer 30

ascending aorta dissection
AR murmur raises suspicion of inferior myocardian infarction AND proximal aortic dissection

Other features may include pericardial effusion, carotid dissection and absent subclavian pulse.

Question 31

What groups is aortic dissection most common in?

Answer 31

Afro-carribean males aged 50-70 years.

Question 32

Describe the pathophysiology of aortic dissection

Answer 32

This occurs when there is a flap or filling defect within the aortic intima. Blood tracks into the medial layer and splits the tissues with the subsequent creation of a false lumen.

Question 33

Where anatomically is aortic dissection more common?

Answer 33

most commonly occurs in the ascending aorta or just distal to the left subclavian artery (less common)