Aortic intramural hematoma and its complications.

It has long been an axiom of mine that the little things are infinitely the most important. C ase Presentation: A 70-year-old woman with hypertension presents for evaluation of a single episode of nonexertional chest pain of moderate intensity, atypical for myocardial infarction. Clinical signs of acute aor-tic dissection and cardiac tamponade are absent. A 12-lead ECG and blood test for troponin are negative for acute myocardial infarction. M-mode trans-thoracic echocardiogram of the aortic root shows dense echoes anteriorly and posteriorly at the level of the aortic valve and a large pericardial effusion (Figure 1A). After discussing a diagnosis of acute aortic syndrome, she asks, " What other tests will I need to confirm the diagnosis? Will I undergo surgery? " Intramural hematoma (IMH) is a life-threatening aortic disease included within acute aortic syndrome, together with aortic dissection and penetrating aortic ulcer (PAU). 2,3 IMH is a contained aortic wall hematoma with bleeding within the media but without initial intimal flap formation (Figure 2). 3 Its natural history is variable ; it may be reabsorbed without any intervention, or it may progress to classic aortic dissection, with outward aor-tic rupture observed in 15% to 20% of patients. Approximately 10% to 30% of patients with acute aortic syndrome have IMH. Similar to acute aortic dis-section, it is classified as Stanford type A (ascending aorta) or B (exclusive involvement of the descending aorta). Most patients with IMH have Stanford type B (50% to 85%). IMH converts to acute aortic dissection in 3% to 14% of patients with involvement of the descending aorta and in 88% of those with involvement of the ascending aorta, with high mortality rates. It is generally recommended that patients with type A IMH undergo early surgery , whereas patients with type B IMH can be managed conservatively in the absence of complications. It is difficult to reliably distinguish IMH from acute aortic dissection and PAU, but clues from patient characteristics , clinical presentation, and noninvasive cardiac diagnostic techniques , including M-mode echocar-diography, can facilitate the diagnosis of IMH. The major complications of acute aortic syndrome, periaortic hematoma and hemorrhagic pericar-dial effusion, occur more frequently in IMH than in acute aortic dissection and can be fatal unless treated on an emergency basis. Computed tomography (CT) and trans-esophageal echocardiography have been used increasingly to diagnose patients with aortic IMH. These methods have advanced our understanding of the pathogenesis of IMH. …