Aortic Dissection Flashcards
Aortic dissection is rare
true
Describe the pathophysiology of aortic dissection
tear in the tunica intima of the wall of the aorta
Which syndromes are associated with aortic dissection?
Turner’s and Noonan’s syndrome
collagens: Marfan’s syndrome, Ehlers-Danlos syndrome
Which infection is associated with aortic dissection?
syphilis
What is the most important risk factor re aortic dissection?
Hypertension
Can pregnancy be associated with aortic dissection
yes
Which valve deformity is associated with aortic dissection
bicuspid aortic valve
Describe the characterstic chest pain associated with aortic dissection?
typically severe, radiates through to the back and ‘tearing’ in nature
What will the pulse be like in aortic dissection?
weak or absent carotid, brachial, or femoral pulse
variation (>20 mmHg) in systolic blood pressure between the arms
Which murmur would you hear in aortic dissection?
aortic regurgitation
Describe how symptoms would manifest if the coronary arteries were involved
angina
Describe how symptoms would manifest if the spinal arteries were involved
paraplegia
Describe how symptoms would manifest if the distal aorta was involved
limb ischaemia
What ECG changes would you see in aortic dissection
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
What two classifications are used for aortic dissection?
Stanford classification
DeBakey classification
Describe the Stanford classification Type A & Type B
type A - ascending aorta, 2/3 of cases
type B - descending aorta, distal to left subclavian origin, 1/3 of cases
Describe the 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
What is the investigation of choice for aortic dissection?
CT angiography of the chest, abdomen and pelvis
Is CT angiography better for stable or unstable patients?
suitable for stable patients and for planning surgery
What will you see on CT angiography?
a false lumen is a key finding in diagnosing aortic dissection
What would you see on CXR?
widened mediastinum
Transoesophageal echocardiography (TOE) is suitable for which patients?
more suitable for unstable patients who are too risky to take to CT scanner
It’s important to remember that patients may present acutely and be clinically unstable.
What classification determines management?
Stanford classification Type A & Type B
How do you manage a Type A dissection?
surgical management,
but blood pressure should be controlled to a target systolic of 100-120 mmHg whilst awaiting intervention
How do you manage a Type B dissection?
conservative management
bed rest
reduce blood pressure IV labetalol to prevent progression
Complications of backward tear?
aortic incompetence/regurgitation
MI: inferior pattern is often seen due to right coronary involvement
Complications of a forward tear?
unequal arm pulses and BP
stroke
renal failure
Why might focal neurological defects present with aoritc dissection?
propagation of the intimal tear to branch arteries
due to mass effects as the expanding aorta compresses surrounding structures
compression of the sympathetic trunk by the expanding aortic dissection would result in what?
Horner’s syndrome (classically ptosis, miosis and anhidrosis)
A 52-year-old male presents with tearing central chest pain. On examination he has an aortic regurgitation murmur. An ECG shows ST elevation in leads II, III and aVF. What is the diagnosis?
ascending aorta dissection
AR murmur raises suspicion of inferior myocardian infarction AND proximal aortic dissection
Other features may include pericardial effusion, carotid dissection and absent subclavian pulse.
What groups is aortic dissection most common in?
Afro-carribean males aged 50-70 years.
Describe the pathophysiology of aortic dissection
This occurs when there is a flap or filling defect within the aortic intima. Blood tracks into the medial layer and splits the tissues with the subsequent creation of a false lumen.
Where anatomically is aortic dissection more common?
most commonly occurs in the ascending aorta or just distal to the left subclavian artery (less common)
