Section: USMLE

50) A 61-year-old man presents with a chief complaint of difficulty swallowing. To evaluate his dysphagia, the physician orders a barium swallow with fluoroscopy, as well as an esophagogram. She finds that the anterior wall of the esophagus in the mid-thorax is being compressed. Which of the following structures is most likely responsible for this compression?

1. Left atrium
2. Right ventricle
3. Left ventricle
4. Pulmonary trunk
5. Right atrium

The left atrium forms most of the posterior wall of the heart. The esophagus passes immediately posterior to the heart. Enlargement of the left atrium may compress the esophagus and cause dysphagia.

The left ventricle forms most of the left border of the heart and most of the diaphragmatic surface of the heart. The left ventricle is not related to the esophagus.

The pulmonary trunk emerges from the right ventricle on the anterior surface of the heart. The pulmonary trunk is not related to the esophagus.

The right atrium forms the right border of the heart. It is not related to the esophagus.

The right ventricle forms most of the anterior wall of the heart and a small portion of the diaphragmatic surface of the heart. It is not related to the esophagus.