Aortic Dissection Flashcards
Define Aortic Dissection?
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
How do we classify Aortic Dissection?
Type A: Ascending Aorta (most common)
Type B: Descending Aorta (distal to the left subclavian artery)
What is Aortic Dissection usually preceded by?
Degenerative changes in the smooth muscle of the aortic media
What are the common causes and risk factors of Aortic Dissection?
Hypertension Aortic Atherosclerosis Connective Tissue disease Congenital cardiac abnormalities (coarctation of the aorta) Aortitis Iatrogenic (e.g. during angioplasty/angiography) Trauma Crack Cocaine
What can expansion of the false lumen lead to?
Obstruction of the subclavian, carotid, coeliac and renal arteries
What can the obstruction of these major arteries lead to?
Hypoperfusion of the target organs of these major arteries can give rise to other symptoms (e.g. carotid artery obstruction leads to collapse)
What is the epidemiology of Aortic Dissection?
Most common in males aged 40-60 years
What is the main presenting symptom of Aortic Dissection?
Sudden central ‘tearing’ pain, it may radiate to the back in between the shoulder blades (it can mimic MI)
What are the other symptoms caused by?
Obstruction of branches of the aorta
What symptoms are caused by obstruction of Carotid Artery in Aortic Dissection?
Hemiparesis
Dysphasia
Blackout
What symptoms are caused by obstruction of Coronary Artery in Aortic Dissection?
Chest pain (angina or MI)
What symptoms are caused by obstruction of Subclavian Artery in Aortic Dissection?
Ataxia
Loss of consciousness
What symptoms are caused by obstruction of Anterior Spinal Artery in Aortic Dissection?
Paraplegia
What symptoms are caused by obstruction of Coeliac Axis in Aortic Dissection?
Severe abdominal pain (due to ischaemic bowel)
What symptoms are caused by obstruction of Renal Artery in Aortic Dissection?
Anuria
Renal Failure
What are the signs of Aortic Dissection on physical examination?
Murmur on the back (below the left scapula), descending to the abdomen
Hypertension
Blood pressure difference between the two arms > 20 mm HG
Signs of Aortic Regurgitation
Unequal arm pulses
There may be a palpable abdominal mass
What do we check for in Aortic Dissection?
Check for pulsus paradoxus
What is pulsus paradoxus?
Abnormally large decrease in systolic bp and pulse wave amplitude during inspiration
What does pulsus paradoxus indicate?
Tamponade
Pericarditis
Chronic Sleep Apnoea
Obstructive Lung Disease
What are the signs of aortic Regurgiation?
High volume collapsing pulse
Early diastolic murmur over aortic area
What investigation would you do for Aortic Dissection?
Bloods CXR ECG CT Thorax Echocardiography Cardiac Catheterisation and aortography
What bloods would we do for Aortic Dissection?
FBC
X-match 10 units of blood
U&E - check renal function
Clotting Screen
What would we see on a CXR for Aortic Dissection?
Widened mediastinum
What might we see on an ECG for Aortic Dissection?
Otften normal
If the ostia of the RCA is compromised you may get signs of:
- Left Ventricular Hypertrophy
- Inferior MI
What would we see on a CT Thorax for Aortic Dissection?
Shows false lumen
Why do we do a Echocardiography for Aortic Dissection?
Transoesophageal allows visualisation
