Aortic dissection (Complete)

Question 1

How does aortic dissection occur?

Answer 1

Tear in the tunica intima causes a false lumen for blood to flow through

Question 2

What are the risk factors for aortic dissection?

Answer 2

Hypertension

Trauma

Bicuspif aortic valve

Connective tissue disorders (e.g. Ehler’s-danlos syndrome, Marfan’s syndrome)

Turner’s syndrome and Noonan’s syndrome

Pregnancy (Due to hormonal effect on vasculature)

Syphillis (Lesions tend to target aorta)

Cocaine/amphetamine use (Produces abrupt severe hypertension)

Question 3

What are the main signs/symptoms of aortic dissection?

Answer 3

Chest/back pain: Ripping in nature

Pulse deficit: Weak or absent: Carotid, brachial or femoral pulse. [Radio-radial delay or Radio-femoral delay]

Variation in systolic blood pressure between both arms

Aortic regurgitation: Newly developed early-diastolic murmur

Hypertension

Symptoms depending on how large the dissection is:

Syncope

Renal failure

Bowel/limb ischaemia

Question 4

What are the main characteristics of aortic dissection chest/back pain?

Answer 4

Pain located in chest or interscapular which radiates to the back

Maximal pain on onset

Described as ripping/tearing

Question 5

What type of murmur is heard in patients with aortic regurgitation?

Answer 5

Early-diastolic murmur

Question 6

What are the two types of aortic dissection according to the Stanford criteria?

Answer 6

Type A: Dissection occured in ascending aorta (2/3rd)

Type B: Dissection occured in descending aorta (1/3rd)

Question 7

What investigations should be done in patients suspected of having aortic dissection?

Answer 7

A-E approach first before investigations as they present acutely unwell

Bedside:
ECG: Non specifc or no ECG changes (May show ischaemia if it affects coronary arteries however)

Bloods:
Troponin: May be raised

D-dimer: May be positive

Imaging:
CXR: Widened mediastinum

CTA: 1st line diagnostic For stable patients with planned surgery. Would show a false lumen.

Transoesophageal echocardiography (TOE): For patients too unstable for CTA

Question 8

When would you choose CTA over transoesophageal ECHO and vice versa?

Answer 8

CTA: For stable patients suitable for surgery

Transoesophageal echocardiography (TOE): For patients too unstable for CTA

Question 9

What is the management plan for aortic dissection?

Answer 9

Conservative:

Resuscitation if neccesary

Cardiac monitoring

Strict BP control (IV mesoprolol/labetalol if needed)

N.B. Type B is mainly conservatively

Surgical: For type A
Aortic graft

N.B. Make sure to stabilise patient e.g. labetalol if hypertensive before surgery

Question 10

How does the management plan differ between type A and B aortic dissections?

Answer 10

Type A can undergoe surgical management (e.g. aortic graft)

Type B is managed mainly conservatively

Question 11

What BP measurements should a patient with type A aortic dissection be within prior to surgical intervention?

Answer 11

100-120mmHg systolic

Question 12

What are some complications that can occur in patients with aortic dissection?

Answer 12

Complications of a backward tear

Aortic regurgitation

Inferior MI: Usually because right coronary artery affected

Complications of a forward tear

Renal failure

Stroke

Unequal arm pulses and BP

Question 13

What type of aortic dissection can be seen on this image?

Answer 13

Type A

Can see flap in the ascending aorta

Question 14

What type of aortic dissection can be seen on this image?

Answer 14

Type B

Can see flap in desecending aorta

Question 15

Why is there emphasis of strict BP control in patients with aortic dissection?

Answer 15

Hypertension can increase the size of the dissection

Question 16

Give 2 examples of medications used in BP control for patients with aortic dissection

Answer 16

IV metropolol

IV labetalol