Introduction

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

Classification

Stanford classification
  • type A - ascending aorta, 2/3 of cases
  • type B - descending aorta, distal to left subclavian origin, 1/3 of cases

DeBakey classification
  • 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

Epidemiology

  • Incidence: 3.00 cases per 100,000 person-years
  • Peak incidence: 70+ years
  • Sex ratio: more common in males 2:1
Condition Relative
incidence
Acute coronary syndrome66.67
Pulmonary embolism23.33
Myocarditis6.67
Pneumothorax5.00
Aortic dissection1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Aetiology

Associations
  • hypertension: the most important risk factor
  • trauma
  • bicuspid aortic valve
  • collagens: Marfan's syndrome, Ehlers-Danlos syndrome
  • Turner's and Noonan's syndrome
  • pregnancy
  • syphilis

Pathophysiology

Tear in the tunica intima of the wall of the aorta

Clinical features

Features:
  • chest pain: typically severe, radiates through to the back and 'tearing' in nature
  • aortic regurgitation
  • hypertension
  • other features may result from the involvement of specific arteries. For example coronary arteries → angina, spinal arteries → paraplegia, distal aorta → limb ischaemia

Management

Type A
  • surgical management, but blood pressure should be controlled to a target systolic of 100-120 mmHg whilst awaiting intervention

Type B*
  • conservative management
  • bed rest
  • reduce blood pressure IV labetalol to prevent progression

Complications

Complications of backward tear
  • aortic incompetence/regurgitation
  • MI: inferior pattern often seen due to right coronary involvement

Complications of forward tear
  • unequal arm pulses and BP
  • stroke
  • renal failure