Acute Aortic Dissection

Abstract

A 27-year-old previously healthy woman presented to the emergency room after the sudden onset of severe chest pain and shortness of breath during the 37th week of pregnancy. Her examination was remarkable for a blood pressure of 118/70 mm Hg, heart rate of 100 bpm, and respiratory rate of 24 breaths per minute. The cardiovascular examination was notable for a soft systolic ejection murmur, and the pulmonary and general examinations were unremarkable. ECG demonstrated sinus tachycardia, and her chest x-ray was normal. A D-dimer level was elevated. She underwent a spiral computed tomography scan to evaluate for pulmonary embolism, which instead demonstrated an acute type A aortic dissection and a very small patent ductus arteriosus. The patient underwent emergency cesarean section, which delivered a viable baby, and repair of the type A dissection. Her aortic valve was trileaflet. She had no features on examination to suggest Marfan syndrome or Loeys-Dietz aneurysm syndrome. Her father had died suddenly at 31 years of age of a “presumed heart attack,” and her paternal uncle had undergone ascending aortic aneurysm resection at 42 years of age. Mutation analysis in this woman detected a heterozygous mutation in MYH11 , confirming familial thoracic aortic aneurysm/dissection (TAA/D). Acute aortic dissection is the most common life-threatening disorder affecting the aorta.1 The immediate mortality rate in aortic dissection is as high as 1% per hour over the first several hours, making early diagnosis and treatment critical for survival. Classification schemes for aortic dissection are based on anatomic involvement of the aortic dissection (Figure 1).2 In the DeBakey classification, type I dissections originate in the ascending aorta and extend to at least the aortic arch; type II dissections involve the ascending aorta only; and type III dissections begin in the descending aorta, usually just distal to the …