Aortic dissection

Question 1

What is aortic dissection?

Answer 1

Aortic dissection is a rare but serious cause of chest pain.

Question 2

What is the pathophysiology of aortic dissection?

Answer 2

It involves a tear in the tunica intima of the wall of the aorta.

Question 3

What is the most important risk factor for aortic dissection?

Answer 3

Hypertension.

Question 4

What are some associations with aortic dissection?

Answer 4

Trauma, bicuspid aortic valve, Marfan’s syndrome, Ehlers-Danlos syndrome, Turner’s syndrome, Noonan’s syndrome, pregnancy, and syphilis.

Question 5

What are the typical features of aortic dissection?

Answer 5

Chest/back pain, typically severe and ‘sharp’, ‘tearing’ in nature.

Question 6

How does the pain present in aortic dissection?

Answer 6

Pain is typically maximal at onset.

Question 7

What is the difference in pain presentation between type A and type B aortic dissection?

Answer 7

Chest pain is more common in type A dissection, while upper back pain is more common in type B dissection.

Question 8

What are some physical exam findings in aortic dissection?

Answer 8

Pulse deficit, weak or absent carotid, brachial, or femoral pulse, and variation in systolic blood pressure between the arms.

Question 9

What are some potential complications of aortic dissection?

Answer 9

Coronary arteries may lead to angina, spinal arteries may cause paraplegia, and distal aorta may result in limb ischaemia.

Question 10

What ECG changes may be seen in aortic dissection?

Answer 10

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

Question 11

What are the types in the Stanford classification of aortic dissection?

Answer 11

Type A - ascending aorta (2/3 of cases); Type B - descending aorta, distal to left subclavian origin (1/3 of cases).

Question 12

What are the types in the DeBakey classification of aortic dissection?

Answer 12

Type I - originates in ascending aorta and propagates; Type II - originates in and is confined to ascending aorta; Type III - originates in descending aorta.

Question 13

What is the Stanford classification for aortic dissection?

Answer 13

Type A - ascending aorta, 2/3 of cases
Type B - descending aorta, distal to left subclavian origin, 1/3 of cases

Question 14

What is the DeBakey classification for aortic dissection?

Answer 14

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 15

What is the investigation of choice for aortic dissection?

Answer 15

CT angiography of the chest, abdomen and pelvis is the investigation of choice.

Suitable for stable patients and for planning surgery; a false lumen is a key finding in diagnosing aortic dissection.

Question 16

What is a key finding on a chest x-ray for aortic dissection?

Answer 16

Widened mediastinum

Question 17

What is the management for Type A aortic dissection?

Answer 17

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

Question 18

What is the management for Type B aortic dissection?

Answer 18

Conservative management, bed rest, and reduce blood pressure IV labetalol to prevent progression.

Endovascular repair of type B aortic dissection may have a role in the future.

Question 19

What are complications of backward tear in aortic dissection?

Answer 19

Aortic incompetence/regurgitation and myocardial infarction (MI) with inferior pattern often seen due to right coronary involvement.

Question 20

What are complications of forward tear in aortic dissection?

Answer 20

Unequal arm pulses and blood pressure, stroke, and renal failure.

Question 21

What is the role of transoesophageal echocardiography (TOE) in aortic dissection?

Answer 21

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