Aortic dissection: features and classification

Aortic dissection: features and classification

• tear in the tunica intima
  tunica intima
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  of the wall of the aorta

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

• chest/back pain
  • typically severe and 'sharp', 'tearing' in nature
  • pain is typically maximal at onset
  • classically chest pain is more common in type A dissection and upper back pain is more common in type B dissection
    chest pain is more common in type A dissection and upper back pain is more common in type B dissection
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    . However, there is considerable overlap and both chest and back pain are present in many patients
• pulse deficit
  pulse deficit
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  • weak or absent carotid, brachial, or femoral pulse
  • variation (>20 mmHg) in systolic blood pressure between the arms
• aortic regurgitation
• hypertension
• other features may result from the involvement of specific arteries. For example:
  • coronary arteries → angina
  • spinal arteries → paraplegia
    paraplegia
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  • distal aorta → limb ischaemia
• 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
  ST-segment elevation may be seen in the inferior leads
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Classification

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

• 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

Stanford type A / DeBakey type I

Stanford type A / DeBakey type II

Stanford type B / DeBakey type III