Aortic Dissection Flashcards
Why is it important not to get an MI and aortic dissection confused?
The treatment for MI (anticoagulation with heparin or thrombolytics) worsens aortic dissection
Patient with aortic dissection. Next steps?
- Intervenous beta blocker
- noninvasive imaging procedure (transesophageal echo, CT angiography, MRI)
- Lower BP if hypertensive
Definition of an abdominal aortic aneurysm? Typically occurs where?
Dilation to more than 1.5 times the normal diameter of the aorta. Below the renal arteries.
Cystic degeneration affects what layer of the aorta? Occurs in what connective tissue disorders?
Elastic media. Marfan’s and Ehlers-Danlos syndrome
Factors predisposing to aortic dissection?
Heart problems: aortic valvular abnormalities,
vessel issues: Cystic degeneration, hypertension, coarctation of the aorta, atherosclerotic disease,
other: pregnancy, surgery or catheterization
Dissection occurs when there’s a sudden tear to what layer? Followed by?
Intima. Followed by propagating dissecting hematoma.
Most important factors causing the propagation of the dissection?
Hypertension and the associated shear forces
How does an aortic dissection cause of organ ischemia or infarction?
Produces an intraluminal intimal flap which can occlude branch arteries
Complications from an aortic dissection?
- Organ ischemia
- Cardiac tamponade (leads to exsanguination)
- Acute aortic regurgitation
Anginal pain versus pain of dissection? (Course, alleviation)
Builds over minutes versus maximal at onset
Alleviating by nitrates versus not
Aortic dissection may cause which murmur?
Early diastolic murmur of aortic sufficiency (especially since most dissections begin close to aortic valve)
Blood pressure of most patients with dissection? Otherwise?
Hypertensive. If hypotensive, suspect aortic rupture, cardiac tamponade, dissection of subclavian artery
Plain chest film on patient with aortic dissection would likely show?
Widened superior mediastinum
Type A versus Type B dissection?
Involves the ascending aorta versus does not involve the ascending aorta
Horner syndrome results from?
Compression of the superior cervical ganglion
Superior vena cava syndrome results from?
Compression of the superior vena cava
Hemopericardium, pericardial tamponade occurs from?
Thoracic dissection with retrograde flow to the pericardium
Bowel ischemia hematuria occurs from a dissection involving?
The mesenteric arteries or renal arteries
Hypertension or different blood pressures in the arms result from a dissection involving what?
Cardiac dissection involving brachiocephalic artery
Hemiplegia results from a dissection involving what?
Carotid artery
Most aortic dissection originate where?
A few centimeters above the aortic valve.
Treatment for type A dissection? Mortality without accepted treatment?
Surgical therapy with replacement of a order and sometimes aortic valve. 90%.
Type B dissections originate where?
In the aortic arch distal to the left subclavian artery
Surgery for type B dissections when?
Surgery performed only for complications such as rupture or ischemia of the branch of the aorta
Aim of medical therapy?
Prevent propagation of the dissection by reducing mean arterial pressure and rate of rise of arterial pressure (Reduces shear forces)
Drugs given for type B dissections?
- Intravenous vasodilators such as sodium nitroprusside (lowers BP) with beta blockers such as metoprolol (lowers shear forces)
- Labetalol
Symptoms of Thoracic aortic aneurysm versus abdominal aortic aneurysm
Tearing pain radiating to the back versus asymptomatic with midline pulsatile mass
Abdominal aortic aneurysm can rupture where? Can lead to?
- Anteriorly. Patient exsanguinates within minutes
2. Posteriorly. Patient bleeds into retroperitoneum and presents with severe lower back or mid abdominal pain
Risk of rupture is related to size of aneurysm. Size to watch for?
Low risk of rupture with 5 cm aneurysm but 10 to 20% risk with 6 cm aneurysms
Elective repair of abdominal aortic aneurysms with what size aneurysm?
5.5 cm
Recommendations for surveillance of abdominal aortic aneurysm?
Imaging at 3-12 month intervals depending on risk of rupture
