A 52-year-old man is brought to the emergency department for evaluation of fever, chills, and malaise. Cardiopulmonary examination reveals a new holosystolic heart murmur that radiates toward the axilla. Blood cultures are obtained, and the patient undergoes transesophageal echocardiography. The ultrasound probe is placed in the midesophagus facing anteriorly, and the cardiac chambers are interrogated. Which of the following chambers is closest to the probe?

Question

A 52-year-old man is brought to the emergency department for evaluation of fever, chills, and malaise.  Cardiopulmonary examination reveals a new holosystolic heart murmur that radiates toward the axilla.  Blood cultures are obtained, and the patient undergoes transesophageal echocardiography.  The ultrasound probe is placed in the midesophagus facing anteriorly, and the cardiac chambers are interrogated. Which of the following chambers is closest to the probe?

Quizplus · Accepted Answer

11ec160b_3557_2eeb_9249_495098478469_MD0001_00 This patient's presentation suggests acute endocarditis, with confirmation pending the results of the blood cultures and cardiac imaging. Transesophageal echocardiography (TEE) uses ultrasound waves generated from within the esophagus to produce clear images of the neighboring cardiac structures. The left atrium makes up the majority of the heart's posterior surface, with the esophagus passing immediately posterior to the heart. Therefore, the esophagus lies within closest proximity to the left atrium. This allows the left atrium, atrial septum, and mitral valve to be particularly well visualized on TEE. Due to its proximity, conditions that result in left atrial enlargement (eg, mitral stenosis or regurgitation) can cause dysphagia through external compression of the esophagus. (Choice B) The left ventricle forms the majority of the inferior (diaphragmatic) surface of the heart and the left border of the heart on frontal chest x-ray. (Choice C) The right atrium, along with the superior vena cava, forms the right lateral cardiac border on frontal chest x-ray. (Choice D) The right ventricle forms the anterior (sternal) surface of the heart and the majority of its inferior border on frontal chest x-ray. Educational objective: The left atrium forms the majority of the posterior surface of the heart and resides adjacent to the esophagus. Enlargement of the left atrium can compress the esophagus and cause dysphagia.

A 52-Year-Old Man Is Brought to the Emergency Department for Evaluation