Gross Anatomy USMLE Step 1 Practice Question
A 56-year-old man presents with cardiac tamponade (BP 92/58, HR 128, RR 22, SpO2 94%). Echocardiography reveals a large pericardial effusion with right atrial collapse. He denies recent chest trauma. He takes aspirin daily for coronary artery disease. Emergency pericardiocentesis is performed using a parasternal approach through the left fifth intercostal space adjacent to the sternum. Which of the following structures is most at risk of inadvertent injury with this anatomic approach?
Answer choices
- AInternal thoracic arteryCorrect answer
- BThoracic duct
- CPhrenic nerve
- DVagus nerve
- EIntercostal artery
- FLeft anterior descending coronary artery
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.