Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (48 page)

   Intramural hematoma accounts for 13% of acute aortic syndromes.

   Aortic rupture is rare outside of trauma but may be seen more commonly in type A dissections.

   Who Should Be Suspected?

   Aortic dissection occurs in the general population of 16.3 and 9.1 per 100,000 in men and women, respectively, with a mean age of 63.

   A classic presentation of “aortic chest pain” is cataclysmic in onset of described as sharp or tearing and may radiate to the chest, jaw, back, or abdomen depending on aortic area involved. Clinical signs of poor prognosis include syncope (cerebral malperfusion), cardiac effusion and tamponade, abdominal pain, and paraplegia (compromised spinal cord perfusion).

   Most common in men older than 60 with hypertension, smoking, and atherosclerosis as risk factors.

   Other acquired risk factors are pregnancy, cocaine/amphetamine use, and inflammatory arthritis (Takayasu, giant cell arteritis, Behchet’s, relapsing polychondritis, SLE,
not
syphilis-induced aortitis).

   Younger populations with aortic syndromes should be suspected of genetic contributions that weaken the medial layer of the aortic (“cystic medial degeneration” or loss of elastin fibers). These include bicuspid aortic valve (most common genetic defect), Marfan syndrome (1:5,000 general population), Ehlers-Danlos syndrome type IV (autosomal dominant, but one half of cases are not inherited), aberrant right subclavian artery, aortic coarctation, Noonan syndrome, and Turner syndrome.

   Diagnosis

   Physical examination: Patients often present acutely ill and accompanied by hypertension. Aortic dissection typically associated with physical signs of murmur of aortic regurgitation (short duration and low pitch), loss of a peripheral pulse (usually femoral), or difference in upper extremity blood pressures. Signs of cardiac tamponade (pulsus paradoxus and elevated jugular venous pressure) should also be assessed.

   Imaging studies:

   ECG: often abnormal, but nondiagnostic. Presence of Q waves or ST elevations (<4%) suggests type A dissection involving the coronary artery ostium (more likely RCA). Avoid thrombolytics.