Snapshot A 55-year-old man presents to the emergency department with chest pain. He describes the pain as excruciating and knife-like that began earlier in the morning. His pain is restricted to the anterior chest. Medical history is significant for hypertension, for which he is taking lisinopril. Physical examination is significant for unequal blood pressures in the arm and a diastolic murmur in the left sternal border. An electrocardiogram is unremarkable, his cardiac troponins are not elevated, and a chest radiograph demonstrates a widened mediastinum. Preparations are made to obtain a CT angiography. Introduction Clinical definition a separation of the media laminal planes, resulting in a blood-filled space in the aortic wall there are two types of aortic dissection Stanford A type a dissection involving the ascending aorta Stanford B type a dissection involving only the descending aorta Etiology hypertension (most common) connective tissue disease iatrogenic (e.g., coronary catheterization) Pathogenesis an intimal tear of the aorta causes an intramural aortic hemorrhage that separates the intima from the media the resulting hematoma may rupture through the adventitia, leading to a thoracic or abdominal cavity hemorrhage or cardiac tamponade Associated conditions Marfan syndrome bicuspid aortic valve Prognosis Stanford type A effective blood pressure control and surgical treatment improves mortality Stanford type B effective conservative or surgical treatment improves mortality Presentation Symptoms acute chest or back pain (most common) classically anterior chest pain that radiates to the back between the scapulae Physical exam unequal blood pressures in the arms weak or absent pulses diastolic decrescendo murmur when the aortic valve is involved resulting in aortic regurgitation Imaging Radiography of the chest indication to rule out other causes of chest pain (e.g., pneumothorax) finding widened mediastinum CT angiography of the chest indication most accurate imaging test for aortic dissection Differential Myocardial infarction differentiating factors an electrocardiogram may be present (e.g., ST-segment elevation) increased cardiac biomarkers Treatment Medical β-blockers indication Stanford type B aortic dissection Surgical vascular surgery indication Stanford type A aortic dissection Complications End-organ damage secondary to poor perfusion Aneurysm rupture