Aortic Dissection

Question 1

Define

Answer 1

DEFINITION: a condition where a tear in the aortic intima allows blood to surge into the aortic wall, causing a split between the inner and outer tunica media, creating a false lumen

Type A: ASCENDING aorta (MOST COMMON)

Type B: DESCENDING aorta (distal to the left subclavian artery)

Question 2

Causes

Answer 2

Predisposed by degenerative changes in the smooth muscle of the aortic media such as:
􏰁 HTN
􏰁 Aortic atherosclerosis
􏰁 Connective tissue disease (SLE, Marfan’s, Ehlers-Danlos)
􏰁 Congenital cardiac abnormalities (e.g. coarctation)
􏰁 Aortitis (Takayasu’s aortitis, tertiary syphilis)
􏰁 Iatrogenic (e.g. during angioplasty, angiography)
􏰁 Trauma
􏰁 Cocaine

Question 3

Risk Factors

Answer 3

HTN
Marfan's
Ehlers- Danlos syndrome 
coarctaction (narrowing)
smoking
family history

Question 4

Symptoms

Answer 4

MAIN SYMPTOM: sudden central ‘tearing’ pain, it may radiate to the back in between the shoulder blades (it can mimic MI)

Other symptoms caused by obstruction of branches of the aorta:

Carotid artery –> hemiparesis, dysphasia, blackout

Coronary artery –> chest pain (angina or MI)

Subclavian artery –> ataxia, loss of consciousness

Anterior spinal artery –> paraplegia

Coeliac axis –> severe abdominal pain (due to ischaemic bowel)

Renal artery –> anuria, renal failure

Question 5

Signs

Answer 5

Murmur on the back (below the left scapula), descending to the abdomen

HTN, BP discrepancy between arms of >20 mmHg

Aortic insufficiency → collapsing pulse, early diastolic
murmur over aortic area, unequal arm pulses

±Palpable abdominal mass

Question 6

Epidemiology

Answer 6

most common in MALES, 40-60 years old

Question 7

Investigations

Answer 7

1. ECG - ST depression
2. Chest xray - may show wide mediastinum
3. Cardiac enzymes - negative - rule out M
4. Computed tomography
5. Renal function test
6. Liver function
7. FBC
8. Surgery type and cross