MEDICAL PROGRESS - DIAGNOSTIC-IMAGING IN THE EVALUATION OF SUSPECTED AORTIC DISSECTION - OLD STANDARDS AND NEW DIRECTIONS (REPRINTED FROM THE NEW-ENGLAND JOURNAL MED, VOL 328, PG 35, 1993)

Acute aortic dissection is a life-threatening condition, and its promp t diagnosis remains essential for successful management. Although earl y mortality may be as high as 1 percent per hour [1] among untreated p atients, survival can be improved by the rapid institution of appropri ate medical or surgical therapy (or both). The Stanford classification system [2] divides aortic dissections anatomically into two types on the basis of location. A dissection in which there is involvement of t he ascending aorta, regardless of the site of entry, is defined as typ e A (this includes De Bakey [3] types I and II and is often described as a proximal dissection). All aortic dissections that do not involve the ascending aorta are defined as type B (these include De Bakey type III and may be referred to as distal dissections). Over the past seve ral decades it has become clear that most patients with type A dissect ions require urgent surgical repair, whereas those with uncomplicated type B dissections can be treated successfully with medical therapy al one. The optimal care of patients with aortic dissection requires that the diagnosis be made promptly and that its site of origin and extent be identified as rapidly as possible. Furthermore, in the age of thro mbolytic therapy for acute myocardial infarction it is crucial to excl ude aortic dissection among patients presenting with syndromes involvi ng chest pain, since the administration of such agents to patients wit h aortic dissection can be catastrophic.