Aortic Dissection Flashcards
Aortic Dissection
A tear in aortic intima through which blood enters and creates a false lumen between intime and media or blood vessels
Classification of AD
Based on:
Anatomical location
- ascending
- descending
Duration of onset:
- acute
- chronic - almost always involved descending aorta
60-7% of aortic dissection involve ascending aorta & are acute in onset
Most common disposing factors for AD
Hypertension
Marfan’s syndrome
Type A AD
Originate in ascending aorta, usually within a few cm of aortic valve, and either
1. extend into descending aorta (type I) or
2. limited to ascending aorta (Type II)
Type B (or Type III) AD
Involve only descending aorta; begins farther down aorta (beyond the arch), and extends into abdominal aorta
Pathophysiology Theory for AD
Attributes nontraumatic aortic dissection to degeneration of elastic fibers in medial layer
- process accelerated by hypertension
- intimal tear typically occur in area with greatest rise in BP like immediately above the aortic valve and just distal to the left subclavian artery
Affects 2-5x more in men
Predisposing factors for AD (8)
Age
Aortic diseases
Atherosclerosis
Blunt trauma
Tobacco
Cocaine or methamphetamine
CHD (bicuspid aortic valve)
connective tissue disorders (Marfan’s syndrome)
Family History
Clinical Manifestations of acute ascending aortic dissection (3)
Sudden, severe, excruciating chest pain, back pain, or both, radiating to neck or shoulders - “sharp” “worst ever”
Usually causes some degree of disruption in coronary artery blood flow & aortic valve insufficiency - may cause angina, MI
Clinical Manifestations of Acute descending aortic dissection (3)
pain in back, abdomen or legs
Clinical Manifestations of aortic arch dissection (4)
May show neurological deficit (altered LOC, weakened or absence of carotid or temporal pulses, dizziness, syncope)
Management - General Approach
Aortic dissection is medical emergency!
Once diagnosis of aortic dissection is suspected, treatment should begin immediately
Type A dissections
High mortality
Requires surgery - involves replacement with a synthetic graft
Type B dissections
Best managed medically
1st line of treatment - management of hypertension with IV beta blockers
- goal is to rapidly decrease systolic BP, pulse pressure, and HR to minimize stress of dissection
- surgery is considered only if complications exist (rupture, renal or limb ischemia, uncontrollable hypertension)
Post-Op nursing care
Similar to that of aortic aneurysm repair
