USMLE PRACTICE QUESTION OF THE WEEK
Question for August 22, 2025
A 52-year-old woman presents with progressive exertional dyspnea and fatigue. Echocardiography shows an enlarged left atrium and normal left ventricular function. Pulmonary artery pressures are elevated.
Which of the following is the most likely cause of her pulmonary hypertension?
Which of the following is the most likely cause of her pulmonary hypertension?
Correct Answer:
B. Left-sided heart failure
Step-by-Step Explanation:
Step 1: Left atrial enlargement with preserved LV function and pulmonary hypertension points toward postcapillary pulmonary hypertension secondary to left-sided heart disease, most commonly heart failure with preserved ejection fraction (HFpEF).
Step 2: Elevated left atrial pressure is transmitted backward to the pulmonary circulation, causing increased pulmonary artery pressures.
Why These Are Incorrect:
- A. Chronic thromboembolic disease would show perfusion defects on imaging.
- C. Primary pulmonary hypertension usually occurs in younger patients and involves small pulmonary arterioles.
- D. Acute pulmonary embolism causes sudden dyspnea but not left atrial enlargement.
- E. Sarcoidosis can cause pulmonary hypertension, but other systemic signs would usually be present.