Aortic dissection

Question 1

Definition

Answer 1

A tear in the intimate of the thoracic aorta, blood rushes through the tear causing the inner and middle laters of the aorta to split (dissect). If the blood goes through the outside aortic wall, aortic dissection is often deadly

Question 2

Aetiology

Answer 2

Caused by a weakened area within the aortic wall

Aortic dissections are divided into 2 groups, depending on which part of the aorta is affected:
– TYPE A- more common and dangerous. Involves a tear in part of the aorta where it exits the heart. The may also occur in the upper aorta (ascending aorta), which may extend into the abdomen

– TYPE B- involves a tear in the lower aorta only (descending aorta), which may also extend into the abdomen

Pre-existing aortic aneurysm

Hypertension (present in 70% of cases of type B dissection)

Atherosclerosis

trauma (most common):
– neck sprain
– whiplash from car accident
– extreme head positions (painting a ceiling for a prolonged period of time)
– carrying heavy objects

Recent illnesses:
– GI upset causing frequent vomiting
– upper respiratory tract infection with persistent coughing

Connective tissue disorders:
– Ehler’s danlos syndrome
– marfans syndrome
– fibromuscular dysplasia
– osteogenesis imperfecta

Also predisposition from autoimmune rheumatic disorders

Question 3

Risk factors

Answer 3

Uncontrolled high blood pressure

Atherosclerosis of arteries (as atherosclerosis is caused by damage to the aortic wall)

Aortic valve defect

Narrowing of the aorta at birth

Question 4

Clinical presentation

Answer 4

Abrupt very severe tearing chest pain, often in the mid scapula area
– this pain may mimic MI and radiate down the left arm

Shortness of breath

Weak pulse in one arm or thigh compared with the other

Leg pain

Difficulty walking

Loss of consciousness

Hoarseness in the voice and Horners syndrome

Hypertension very common with AAD, if the pt presents with hypotension then it is more seen as a rupture

Symptoms similar to those of a stroke, including sudden vision problems, difficulty speaking and weakness or loss of movement (paralysis) on one side of your body

Signs:
– may be shock
– may develop neurological symptoms secondary to loss of blood supply to the spinal cord
– aortic regurgitation (where the aortic valve doesn’t close tightly)
– coronary ischaemia
– cardiac tamponade (where fluid accumulates in the pericardial sac, medical emergency)