Aortic Dissection Flashcards
Definition
Tear in intima resulting in blood dissecting through media
Surgical emergancy
Separating layers apart
Epidemiology
MEN
50-70
Risk factors
Due to mechanical wall stress
HTN
Connective tissue disorders (M,ED)
FHx of AAA/AD
Trauma
Smoking
Aetiology/ Most common locations for aortic dissection
STANFORD CLASSIFICATION (Location)
1/A. Sinotubular junction - where aortic root becomes ‘tubular’ aorta, near aortic valve = MOST COMMON.
2/B. Just distal to left subclavian artery (in descending thoracic aorta)
Pathology
Tear in intimal layer of aorta = collection of blood between intima + medial layers.
Blood dissects media + intima + pools in false lumen which can propagate fowards (anterograde - toward aortic root) or backwards (retrograde) -> decreased perfusion to end organs; organ failure + shock
Signs and symptoms
SUDDEN ONET RIPPING/TEARING CHEST PAIN
Shock/hypotension
New aortic insufficiency murmur (aortic regurgitation),
Neurology deficit (affected carotid perfusion) e.g. syncope
Decrease in left arm peripheral pulse (radial decrease if subclavian involved), cardiac tamponade or radial differences L/R arms (10mmHg + pressure)
Diagnosis
CXR - widened mediastinum -> 8cm SUSPICIOUS
GOLD STANDARD = TOE = shows intimal flap + false lumen (more invasive than TTE but more specific for AD, and v.sensitive)
Then classify A or B
CT angiogram (also v.specific + sensitive) -> intimal flap, false lumen, rupture/leak
- used more if Px haemodynamically patient
Treatment
Surgical = open repair (typically A) or endovascular repair (more B)
If hypotensive = consider IV fluid, blood transfusion + adrenaline
Medical (prevention) = AIM (SBP 100-120, HR - 60s)
FIRST LINE = SPECIAL BB = ESMOLOL or LABETOLOL
* beta-blocker + partial a/b; prevents reflex tachycardia = decrease BP
SECOND LINE = vasodilator = SODIUM NITROPRUSSIDE
Complication
Cardiac tamponade
Aortic insufficiency (regurg)
Pre-renal AKI
Stroke (Ischaemic)
