Aortic Dissection Flashcards
What is an aortic dissection?
Tear in the tunica intima in wall of aorta
What is the biggest RF for aortic dissection?
HTN
List 6 risk factors other than HTN for aortic dissection
Trauma
Bicuspid aortic valce
CTD: Marfan’s, EDS
Turner’s + Noonan’s
Pregnancy
Syphillis
Recall 2 ways in which aortic dissection can be classified and what these entail
Stanford classification
Type A: ASCENDING aorta (2/3 cases)
Type B: DESCENDING aorta (1/3 cases)
De Bakey classification
Type 1 originates in ASCENDING aorta, EXTENDs to arch + possibly beyond
Type 2: confined to ASCENDING aorta
Type 3: originates in DESCENDING aorta
What is the main symptom of aortic dissection?
Tearing chest/ back pain
Maximal at onset
Describe classic pain in type A and B dissection?
Type A: Chest pain more common
Type B: Upper back pain more common
(overlap + often both present)
What signs may be found in aortic dissection?
Pulse deficit
Aortic regurgitation
HTN
What pulse deficit is seen in aortic dissection?
Weak/ absent carotid, brachial or femoral pulse
Variation >20mmHg in SBP between arms
List 3 features caused by involvement of specific arteries in aortic dissection
Coronary arteries: Angina
Spinal arteries: Paraplegia
Distal aorta: limb ischaemia
What ECG changes are seen in aortic dissection?
Majority: none/ non-specific changes
Minority: ST elevation in inferior leads
What would be seen on CXR in aortic dissection?
Widened mediastinum
How should aortic dissection be imaged?
Stable: CT CAP (Ix of choice)- false lumen
Unstable: Transoesophageal echo
Describe management of Type A aortic dissection
Surgical emergency: refer to surgeons
Meanwhile: control BP + analgesia
What is used to control BP in Type A aortic dissection?
IV Labetalol
If AR/ CI: Verapamil/ Diltiazem
Then vasodilate: Sodium nitroprusside
Why must B-blockers be avoided in aortic regurgitation?
B-blockers can inhibit compensatory tachycardia.
What analgesia is given in aortic dissection?
Morphine sulfate
To reduce pain + stress that increases HTN + tachycardia
What surgical intervention is performed in Type A aortic dissection?
Open surgery: replacement of dissection with graft
In which type of aortic dissection is emergency surgery not indicated?
Descending
Describe management of Type B aortic dissection
Conservative: watchful waiting + medication unless complications occur
B-blocker to reduce BP + prevent progression
+/- ARB/ ACEi
Lifestyle: avoid contact sports, smoking cessation
When is surgical repair of type B aortic dissection performed?
Electively: Open replacement + graft implantation/ endovascular aortic stent implantation
If complications arise: open
Name 5 complications of type A aortic dissections
MI (coronary artery occlusion; inferior pattern often seen due to RCA involvement)
Aortic regurgitation
Cardiac tamponade
Pericarditis
Stroke (extension of dissection into carotids)
Name 2 complications of both type A and B aortic dissections
Aortic rupture + acute blood loss
Arterial occlusion followed by ischaemia of downstream organs
What occurs secondary to ischaemia of the celiac trunk/ superior/ inferior mesenteric artery?
Acute abdomen
Ischaemic colitis
What occurs secondary to ischaemia of the renal arteries?
Acute renal failure
What occurs secondary to ischaemia of the spinal arteries?
Weakness of lower extremities or acute paraplegia
What occurs secondary to complete occlusion of the distal aorta?
Leriche syndrome (Aortoiliac occlusive disease)
Classic triad of:
Bilateral buttock, hip, or thigh claudication
Erectile dysfunction
Absent/ diminished femoral pulses.
