A 78-year-old man is brought to the emergency department due to an episode of syncope while working in his garden. He is now alert and oriented. He has chest and neck pain that developed just prior to the syncopal episode. Over the past week, he has had a cough, chest tightness, and whitish sputum production. Medical history is significant for long-standing hypertension, hyperlipidemia, and type 2 diabetes mellitus. The patient is a lifetime nonsmoker. Temperature is 37.3 C (99.2 F), blood pressure is 144/92 mm Hg on the right arm and 142/90 mm Hg on the left arm, and pulse is 109/min. ECG shows sinus tachycardia, voltage criteria for left ventricular hypertrophy, and no ST-segment or T-wave changes. Chest x-ray is shown in the exhibit. A bedside transthoracic echocardiogram shows a small pericardial effusion. Which of the following is the best next step in management of this patient?

Question

A 78-year-old man is brought to the emergency department due to an episode of syncope while working in his garden.  He is now alert and oriented.  He has chest and neck pain that developed just prior to the syncopal episode.  Over the past week, he has had a cough, chest tightness, and whitish sputum production.  Medical history is significant for long-standing hypertension, hyperlipidemia, and type 2 diabetes mellitus.  The patient is a lifetime nonsmoker.  Temperature is 37.3 C (99.2 F), blood pressure is 144/92 mm Hg on the right arm and 142/90 mm Hg on the left arm, and pulse is 109/min.  ECG shows sinus tachycardia, voltage criteria for left ventricular hypertrophy, and no ST-segment or T-wave changes.  Chest x-ray is shown in the exhibit.  A bedside transthoracic echocardiogram shows a small pericardial effusion.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d89f_a260_bc81_112cfe171a41_MD0003_00 Although this patient does not have severe chest pain or a pulse differential, his chest and neck pain, syncope, history of hypertension, evidence of mediastinal widening on chest radiograph, and pericardial effusion are all concerning for acute aortic dissection. Pulse differential blood pressure in the upper extremities is an important clinical sign but is present in only 20%-30% of patients; its absence should not be used to exclude aortic dissection. Type A (ascending aorta) dissections can lead to aortic rupture into the pericardial space and hemopericardium, which can rapidly progress to cardiac tamponade and cardiogenic shock. chest radiograph As type A aortic dissections are surgical emergencies with mortality rates of 1%-2% per hour following symptom onset, confirming or excluding the diagnosis is critical: CT angiography is the initial study of choice in hemodynamically stable patients with no evidence of renal dysfunction. It can reveal an intimal flap separating the true and false lumens in the aorta. MR angiography is more time consuming and requires the administration of gadolinium-containing contrast agents for contrast enhancement; it should be avoided in patients with moderate to severe kidney disease due to the risk of nephrogenic systemic fibrosis. Transesophageal (not transthoracic) echocardiography has excellent sensitivity and specificity and is the preferred diagnostic study in patients with hemodynamic instability or renal insufficiency; a transthoracic echocardiogram may not visualize parts of the aorta well. (Choice A) Although this patient may initially have had bronchitis (cough with whitish sputum production and chest discomfort), his current presentation is suggestive of acute aortic dissection. Furthermore, there is no consolidation or infiltrate on chest x-ray; therefore, antibiotics are not indicated. Sudden, transient increases in blood pressure (eg, cocaine use, heavy lifting, cough) can precipitate acute aortic dissection. (Choice B) Beta blockers are typically used to lower systolic blood pressure in acute aortic dissection. However, the use of anticoagulants in patients with suspected aortic dissection and possible hemopericardium is contraindicated. (Choice C) This patient's ECG shows sinus tachycardia along with left ventricular hypertrophy due to long-standing hypertension. There is no indication for cardiac catheterization at this point, and it would likely cause a further delay in definitive diagnosis and management. (Choice E) Emergency pericardiocentesis is indicated in patients with pericardial effusion and cardiac tamponade (eg, Beck's triad with hypotension, dilated neck veins, and muffled heart sounds) with hemodynamic instability or cardiogenic shock. This patient is hemodynamically stable and has a small pericardial effusion; therefore, emergency pericardiocentesis is not indicated and may lead to complications and therapeutic delay in case the diagnosis of type A dissection is missed. Educational objective: Acute type A aortic dissection can extend into the pericardial space, causing hemopericardium and rapidly progressing to cardiac tamponade and cardiogenic shock. CT angiography is the initial diagnostic study of choice in hemodynamically stable patients and reveals an intimal flap separating the true and false lumens in the ascending or descending aorta. References: Missed diagnosis of limited ascending aortic dissection by multiple imaging modalities leading to fatal cardiac tamponade and aortic rupture. (http://www.ncbi.nlm.nih.gov/pubmed/21827545) Obstacles in the diagnosis of acute aortic dissection. (http://www.ncbi.nlm.nih.gov/pubmed/15138102) Corrigendum to: 2014 ESC Guidelines on the diagnosis and treatment of aortic diseases. (http://www.ncbi.nlm.nih.gov/pubmed/26129948)

A 78-Year-Old Man Is Brought to the Emergency Department Due