A 70-year-old man comes to the emergency department due to severe midback pain that started several hours ago. He describes the pain as excruciating and wants immediate relief. The patient also has nausea, diaphoresis, and lightheadedness. He has a history of hypertension and chronic kidney disease. His medication compliance has been poor. He is an active smoker with a 40-pack-year history. His blood pressure on the right arm is 220/105 mm Hg. ECG shows sinus tachycardia and voltage criteria for left ventricular hypertrophy with secondary ST-segment and T wave changes. After initial evaluation, a transesophageal echocardiogram shows a dissection flap in the descending aorta but no evidence of dissection in the ascending aorta. The dissection flap in this patient most likely originates near which of the following points?

Question

A 70-year-old man comes to the emergency department due to severe midback pain that started several hours ago.  He describes the pain as excruciating and wants immediate relief.  The patient also has nausea, diaphoresis, and lightheadedness.  He has a history of hypertension and chronic kidney disease.  His medication compliance has been poor.  He is an active smoker with a 40-pack-year history.  His blood pressure on the right arm is 220/105 mm Hg.  ECG shows sinus tachycardia and voltage criteria for left ventricular hypertrophy with secondary ST-segment and T wave changes.  After initial evaluation, a transesophageal echocardiogram shows a dissection flap in the descending aorta but no evidence of dissection in the ascending aorta.  The dissection flap in this patient most likely originates near which of the following points?

Quizplus · Accepted Answer

11ec160b_3553_5e50_9249_279640fa704f_MD0001_00 This patient's clinical presentation with severe back pain, hypertension, ECG abnormalities, and transesophageal echocardiogram finding of a dissection flap in the descending aorta is consistent with Stanford type B aortic dissection. The Stanford system uses the anatomic localization of the dissection plane for classification of aortic dissections: Type B dissections involving the descending aorta typically originate close to the origin of the left subclavian artery. Type A aortic dissections usually originate in the sinotubular junction. The areas are thought to be predominantly affected due to increases in the rate of rise of pressure (dP/dT) and in shearing forces at these sites in patients with severe hypertension. (Choices A, B, C, and E) Distal propagation of a type A dissection or proximal propagation of a type B dissection can affect the aortic arch (eg, brachiocephalic artery, left common carotid artery, left subclavian artery). Either type of dissection can propagate distally into the thoracoabdominal aorta, involving the origins of the celiac trunk, intercostal arteries, and renal arteries. Educational objective: The intimal tear in Stanford type A aortic dissection (involving the ascending aorta) usually originates in the sinotubular junction whereas the intimal flap in Stanford type B aortic dissection usually starts near the origin of the left subclavian artery. Dissections can propagate distally to the thoracoabdominal aorta.

A 70-Year-Old Man Comes to the Emergency Department Due to Severe