title: Aortic dissection.
abstract: Aortic root enlargement is generally asymptomatic, with few clinical clues, but may be observed as an incidental finding on a chest x-ray, echocardiogram, or contrast-enhanced computerized tomogram of the chest. Aortic dissection is one of the most feared complications of hypertension. A history of hypertension is commonly present, but the systolic blood pressure in type A dissection (proximal to the left subclavian artery) has been found to be less than 150 mm Hg in 64% of patients. However, 71% of type B dissections (distal to the left subclavian artery) present with a systolic blood pressure 150 mm Hg or higher (International Registry of Acute Aortic Dissection). Most frequently, onset of symptoms is in the daytime, especially between 6 a.m. and noon. Severe sharp chest pain that is abrupt in onset is the most likely presentation. Migrating pain is uncommon. Although a pulse deficit with decreased or absent carotid, brachial, or femoral pulses occurs in only 30% of patients, three or more deficits predict an in-house mortality of about 60%. A chest x-ray finding of a widened mediastinum is present in 62.6% of type A and 56% of type B dissections. Contrast-enhanced computerized tomography or transesophageal echocardiography is the most commonly performed procedure for diagnosis. In-house mortality has been found to be 32.5% in type A dissections and 13% in type B dissections.
authors.affiliation: Hypertension and Clinical Pharmacology, Medical College of Georgia, Augusta, GA 30912, USA. mprisant@mail.mcg.edu
authors.forename: L Michael
authors.initials: LM
authors.lastname: Prisant
authors.forename: V R Prasad
authors.initials: VR
authors.lastname: Nalamolu
mesh_terms: D000208:Acute Disease; D000784:Aortic Dissection / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D001014:Aortic Aneurysm / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D003952:Diagnostic Imaging; D006801:Humans; D006973:Hypertension / Q000150:complications; D015994:Incidence; D012307:Risk Factors; D015996:Survival Rate; D014481:United States / Q000453:epidemiology