Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + • Often lethal event• Degeneration of aortic media is hallmark of disease• Pathogenesis controversial 1. Medial degeneration leads to rupture of vasa vasorum2. Intimal tears allows blood to shear weakened media• Location of intimal tear: Ascending aorta, 62%; arch, 10%; isthmus, 16%; rest in distal aorta• Risk factors include: -Hypertension-Atherosclerosis-Iatrogenic injury (catheter or open heart surgery)-Closed chest trauma-Marfan syndrome-Aortic coarctation +++ Classification + • Debakey type I-Originate in ascending aorta-Extend beyond left subclavian (Stanford type A)• Debakey type II -Involve ascending aorta only-Often chronic-Associated with aortic valve incompetence (Stanford type A)• Debakey type III -Occur distal to left subclavian artery-Often extend into abdominal aorta (Stanford type B) +++ Epidemiology + • Most common cause of aortic rupture• 2000 cases yearly• Men affected more often than women• Usually occurs in fifth to seventh decades of life +++ Symptoms and Signs + • Most common-Severe, tearing chest pain often signifies intimal tear and formation of false lumen-Ascending: Pain anterior-Descending: Pain posterior between scapulas• Hypotension with blood loss, leak into pericardium• Sudden death if extends into pericardium or down a coronary artery• If involves aortic valve or root, aortic insufficiency and acute congestive heart failure• Obstruction of aortic branch vessels:-Stroke-Asymmetric extremity pulses-Paraplegia-Renal failure-Acute mesenteric ischemia-Lower extremity occlusion +++ Laboratory Findings + • ECG: Useful to rule out myocardial infarction (MI)• Cardiac enzymes: Rule out MI +++ Imaging Findings + • Chest film-50% have widened mediastinum-Cardiomegaly if in failure or with pericardial effusion-Left pleural effusion if contained rupture• Chest CT: Diagnostic procedure of choice• Transesophageal echocardiography (TEE)-Information about myocardial function-Aortic valve competence-Diagnostic-Limited in evaluation of arch and descending dissections• Magnetic resonance angiography (MRA): Useful but time-consuming +++ Rule Out + • MI + • Physical exam• ECG• Chest x-ray• Chest CT scan• Transesophageal echocardiogram• MRA if stable + • Aggressive blood pressure control critical; esmolol commonly used (decreases dP/dT and aortic shear force) +++ Ascending + • Death occurs from cardiac tamponade, acute coronary occlusion, acute atrial regurgitation• Replacement of ascending aorta with resection of intimal tear• Resuspension of aortic valve commissures restores valve competence +++ Descending + • Majority have benign course• Medical therapy treatment of choice• 20% require surgery for rupture or organ ischemia• 20% develop aneurysmal dilation of aorta requiring surgery• Endovascular stent procedure and fenestration are new approaches being studied +++ Medications + • β-Blockers (esmolol)• Vasodilators if still hypertensive after β-blockade... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth