UMSLE case (Thanks Erica!!)

A 62-year-old man with a history of poorly controlled hypertension comes to the emergency department complaining of 1 hour of intense pain in his chest. He was climbing the stairs at home when he felt a sudden, sharp pain in the center of his chest, and felt light-headed. He still feels light-headed and reports that the pain is a “stabbing,” 10 out of 10 pain that radiates throughout his chest. He denies any other medical history, but on further questioning reveals that he smokes one pack of cigarettes daily and takes his metoprolol only when he feels “sick” or has a headache. Vital signs include a temperature of 37.0°C (98.6°F), blood pressure of 170/100 mm Hg, pulse rate of 85/min, and respiratory rate of 15/min. Physical examination shows a well-developed, well-nourished, uncomfortable man with slight diaphoresis. His HEENT and neck examinations are unremarkable. His lung fields are clear to auscultation and he has good breath sounds bilaterally. His heart has a regular rate and rhythm with a 2/6 diastolic murmur along the right sternal border. Examination of his extremities reveals an absent right radial pulse. His abdominal and neurologic examinations are unremarkable. X-ray of the chest shows clear lung fields and a widened mediastinum.

What is the most likely diagnosis? The sudden onset of sharp or “tearing” chest pain should immediately suggest an acute aortic dissection, one of the most life-threatening causes of chest pain. The pulse deficit in the right upper extremity, light-headedness, and widened mediastinum on chest x-ray further point to aortic dissection. These findings also indicate that the dissection is occurring in the ascending aorta and involves at least the right brachiocephalic and right common carotid arteries. Tobacco use and hypertension are the two most common risk factors for aortic dissection. 

How is this condition classified? Aortic dissections are classified using one of two anatomic systems: The DeBakey classification: Type 1: Dissection of ascending and descending thoracic aorta Type 2: Dissection of ascending aorta only Type 3: Dissection of descending aorta only The Stanford classification: Type A: Any dissection involving the ascending aorta Type B: All other dissections
Given his light-headedness (may reflect carotid artery involvement) and the murmur (may represent aortic insufficiency), this patient likely has a Stanford type A dissection.
In addition to tobacco use and hypertension, what other risk factors are often present in patients with this condition? Aortic coarctation. Bicuspid aortic valve. Collagen disorders (e.g., Marfan’s syndrome, Ehlers-Danlos syndrome). Crack cocaine use. Inflammatory vascular disorder (e.g., Takayasu’s arteritis, giant cell arteritis, rheumatoid arthritis, syphilitic aortitis). Preexisting aortic aneurysm. Previous cardiac procedures (e.g., aortic valve replacement, cardiac catheterization, coronary artery bypass grafting). Turner’s syndrome.  
What is the most appropriate treatment for this condition? Dissections involving the ascending aorta are surgical emergencies, whereas dissections confined to the descending aorta are initially treated medically. Hemodynamically unstable patients should be intubated and undergo transesophageal echocardiography (TEE) at the bedside. Intravenous β-blockers should be titrated to the lowest tolerable blood pressure. Patients may present with hypotension for a variety of reasons, including blood loss, cardiac tamponade, or cardiac muscle failure; therefore, inotropic agents should be avoided until the etiology of hypotension is established. Definitive management in this patient with a presumed Stanford type A dissection is prompt surgical repair.