A 68-year-old woman presents to the emergency department with sudden-onset, severe chest pain radiating to her back. The pain started one hour ago and is described as sharp and tearing. She has a history of chronic hypertension, hyperlipidemia, and sick sinus syndrome resulting in placement of a pacemaker. Her blood pressure is 180/100 mm Hg in the right arm and 150/90 mm Hg in the left arm. Her heart rate is 110/min. On physical examination, she appears anxious and diaphoretic and is tachycardic. An electrocardiogram shows a paced rhythm with nonspecific ST-segment and T-wave changes. Chest x-ray reveals mediastinal widening. It is unknown if the pacemaker is MRI compatible at this time in the emergency department.
Which of the following is the most appropriate next step in management of this patient?
D) Transesophageal echocardiography
This patient’s presentation of sudden-onset, severe, sharp, tearing chest pain radiating to the back, significant blood pressure difference between the arms, and mediastinal widening on chest x-ray is highly suggestive of acute aortic dissection. The immediate goal is to confirm the diagnosis and determine the extent and location of the dissection to guide treatment.
Recommendations for cardiovascular imaging are based on consensus guidelines. Multiple imaging modalities can be used to demonstrate the dissection, including chest magnetic resonance (MR) angiography, computed tomographic (CT) angiography, and transesophageal echocardiography (TEE). Each has its advantages and disadvantages, and one may be more appropriate for selected patient populations as an initial study. CT is the most common initial choice due to its widespread availability, particularly in the emergency department setting, though it was not an answer choice in this question. For patients with suspected aortic dissection, particularly when they are hemodynamically unstable or in significant pain, transesophageal echocardiography (TEE) is often the preferred imaging modality. TEE is highly sensitive and specific for aortic dissection and can be performed rapidly at the bedside or in the operating room, providing real-time images that help in confirming the diagnosis and assessing the need for urgent surgical intervention.
Answer choice A: Aspirin administration and measurement of serial troponins, is incorrect. These are part of the workup for acute coronary syndrome (ACS), which presents differently and would not address the aortic dissection.
Answer choice B: Coronary angiography. Emergency coronary angiography is indicated for ST-segment elevation myocardial infarction (STEMI), not for aortic dissection.
Answer choice C: Magnetic resonance angiography of the chest, is incorrect. MR angiography of the chest: Although magnetic resonance (MR) angiography is an imaging modality that can be used to diagnose aortic dissection, it is more time-consuming and less practical for hemodynamically unstable patients. Importantly, the patient has a pacemaker and it is unclear if it is MRI compatible from the information provided in the vignette.
Answer choice E: Ventilation-perfusion lung scan, is incorrect. Ventilation-perfusion lung scan is used to diagnose pulmonary embolism, which would not explain the findings described in this patient.
Key Learning Point
In suspected acute aortic dissection, characterized by sudden-onset severe chest pain radiating to the back and a significant blood pressure difference between the arms, transesophageal echocardiography is the preferred diagnostic test for hemodynamically unstable patients, due to its high sensitivity, specificity, and rapid bedside application.
