submitted by Christina Brown, M.D.
Definition – Blood entering intimal tear in aortic wall. Blood subsequently dissects through the media under aortic systolic pressure.
Risk Factors – HTN, Tobacco abuse, pregnancy, congenital heart disease (bicuspid AV, Coarctation), Marfan’s, Ehler’s Danlos, Inflammation (Lupus, syphilis, endocarditis, GCA)
Location:
Proximal – Occur at the aortic root, coronary ostia and/or pericardium.
Distal – Dissect distally to involve any or all branches of the aorta ie -carotid and subclavian arteries.
Stanford classification:
- Type A: Ascending aorta
- Type B: Distal to ascending aorta
Peak Age for Occurrence
- Proximal dissection: 50–55 yr
- Distal dissection: 60–70 yr
Complications:
- Occlusion of the coronary ostia, aortic valve incompetence, or cardiac tamponade.
Signs & Symptoms
Chest Pain:
- May be absent in as many as 15% of patients
- Acute onset, sharp
- Substernal -> type A dissection
- Intrascapular -> descending thoracic dissection
- Lumbar -> abdominal aorta involvement
Back pain:
- Commonly interscapular or lumbar. May present as combination of chest, back, and abdominal pain.
Neurologic complaints: Stroke symptoms, Vision changes
Physical Exam
Hypertension: 35–40% may be normotensive.
Pulse deficits: Discrepancies in BP in upper extremities
Neurologic/spinal cord deficits
New murmur of aortic regurgitation: Occurs in up to 31% of patients
Management
EKG – Dissection may involve coronary ostia and cause MI:
- Inferior MI (RCA territory) is more common than LCA territory.
- A normal EKG + severe, acute-onset chest/back pain/shortness of breath – high suspicion for aortic dissection.
Labs
- CBC, BMP, UA – Evaluate renal function, hematuria
- Amylase – May be elevated d/t bowel ischemia
- Troponin – May be elevated d/t myocardial ischemia
Imaging
Unstable Patient:
CXR – Widened mediastinum or abnormal aortic contour.
Echocardiogram – Transthoracic vs Transoesophageal (if intubated) – Tamponade, valvular incompetence for evaluation.
Stable Patient: CT, Aortography
ED Treatment
BP Control = Reduce shear force on aortic wall and slow down the dissection process.
- Esmolol (IV) or labetalol (IV): Start before Nitroprusside therapy to prevent reflex tachycardia.
- Contraindications:Bradycardia, COPD, hypotension
- Nitroprusside
Emergent surgery:
- Treatment of choice for type A dissection
- Treatment for type B dissections in those who have failed medical therapy
Medical management:
- Treatment of choice for stable type B dissections
Disposition
ADMIT – All patients with an evolving aortic dissection should be admitted to the ICU. C/S cardiothoracic surgery for type A dissection.
References
1] Jeffrey I. Schneider and Jonathan S. Olshaker. Aortic Dissection, Thoracic. Rosen & Barkin’s 5-minute Emergency Medicine Consult.
2] Erbel R, Alfonso F, and Boileau C et al.: Diagnosis and management of aortic dissection. Eur Heart J. 2001; 22(18):1642–1681. [PMID: 11511117]
[3] Hagan P G, Nienaber C A, and Isselbacher E M et al.: The international registry of acute aortic dissection: New insights into an old disease. JAMA. 2000; 283(7):897–903. [PMID:10685714]
[4] Khan I A and Nair C K.: Clinical, diagnostic, and management perspectives of aortic dissection. Chest. 2002; 122(1):311–328. [PMID: 12114376]
[5] Klompas M.: Does this patient have an acute thoracic aortic dissection? JAMA. 2002; 287:2262–2272. [PMID: 11980527]
[6] Mészáros I, Mόrocz J, and Szlávi J et al.: Epidemiology and clinicopathology of aortic dissection. Chest. 2000; 117(5):1271–1278. [PMID: 10807810]
[7] Moore A G, Eagel K A, and Bruckman D et al.: Choice of computed tomography, transesophageal echocardiography, magnetic resonance imaging, and aortography in acute aortic dissection: International registry of acute aortic dissection. Am J Cardiol. 2002; 89:1235–1238. [PMID:12008187]
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