Type I Type II Current management of type B aortic dissection Type III Figure 3A Debakey classiﬁcation. patients may ascribe a migratory quality to the pain (“I feel like the pain was going from my chest down to my legs”). The pain may wax and wane, sometimes with complete resolution of symptoms. In up to 4.5% of patients with aortic dissection, there was no pain reported. The absence of pain thus does not rule out an aortic dissection although it lowers the likelihood of a dissection (likelihood ratio, LR 0.3).9 In addition to the chest/back/abdominal pain, patients may present with generalized symptoms of dyspnea, diaphoresis, bloody diarrhea, nausea, and vomiting. These nonspeciﬁc symptoms, however, may be the prodrome of the ominous malperfusion syndrome. The clinical manifestation of the malperfusion syndrome depends on the anatomy of the affected vessels. Patients may present with signs or symptoms of a stroke, dizziness/syncope/aphasia/hemiplegia, if they have dynamic obstruction and malperfusion of coronary/ carotid/vertebral arteries. Alternatively, patients may complain of painful, plegic, pulseless, and cool extremities if the brachiocephalic, left subclavian arteries, distal aorta, iliac arteries are compromised. A dramatic paraplegia or quadriplegia is observed when the intercostal/segmental arteries are obstructed, resulting in reduced blood ﬂow in the anterior spinal arteries and ischemic spinal cord. Abdominal pain and decreased urine output is a common malperfusion Vascular Health and Risk Management 2009:5 syndrome that results from obstruction of celiac trunk, superior mesenteric, inferior mesenteric, renal arteries caus- ing (frequently fatal) acute bowel ischemia and decreased renal blood ﬂow and glomerular ﬁltration. The physical examination overall is deemed not sufﬁciently sensitive to rule out an acute aortic dissection.9 However, the examination can be useful in raising the likelihood of an aortic dissection and whether a patient with a probable aortic dissection may need emergent surgical intervention. When performing the physi- cal examination, the ED physician should focus on the assessment of hemodynamic stability, prognostic signs of poor outcome, and signs of impending cardiovascular collapse. The ﬁndings of pulse deﬁcits, blood pressure dif- ferential of at least 20 mm Hg, or motor and sensory deﬁcits on neurological examination signiﬁcantly raise the likelihood ratio (LR 5.7) of an aortic dissection.9 A diastolic murmur of aortic regurgitation indicates possible involvement of the root of the ascending aorta. In a patient with hypotension, the presence of jugular venous distension or pulsus paradoxus indicates pericardial involvement and/or tamponade. These ﬁndings should prompt the clinician to seek emergent diag- nostic conﬁrmations and, at the same time, arrange for prompt cardiothoracic evaluation and intervention. 57