A 27-year-old woman is admitted with cough, shoness of breath, and palpitations. She has been relatively well for most of her life, but her mother gives a history that the patient had recurrent “pneumonia” as a child. The patient denies any sputum production. On examination, she appears anxious. Her neck veins are distended and she has a widened split second hea sound with little respiratory variation. A systolic ejection murmur in the pulmonic area is noted. Lung exam reveals bilateral crackles; mild ascites and pedal edema are also noted. EKG shows right axis detion. CXR is shown in.. The next diagnostic step is

**Core Concept**
The patient's presentation is suggestive of a cardiac condition that has led to pulmonary congestion and right heart failure. The widened split second heart sound with little respiratory variation and the presence of a systolic ejection murmur in the pulmonic area are indicative of increased flow across the pulmonary valve.

**Why the Correct Answer is Right**
The patient's symptoms and signs are consistent with Eisenmenger's syndrome, a condition characterized by pulmonary hypertension and reversal of the left-to-right shunt seen in conditions like ventricular septal defect (VSD). The increased pressure in the pulmonary artery causes the right ventricle to fail, leading to right heart failure and symptoms like shortness of breath, palpitations, and distended neck veins. The widened split second heart sound is due to the increased flow across the pulmonary valve, while the systolic ejection murmur is due to the increased flow across the pulmonary valve.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because a right ventricular infarction would typically present with a different set of symptoms, including chest pain and a different ECG pattern.

**Option B:** This option is incorrect because a pulmonary embolism would typically present with sudden onset of dyspnea, tachycardia, and possibly a pleuritic chest pain.

**Option C:** This option is incorrect because a patent foramen ovale would typically present with a history of paradoxical embolism or migraine headaches.

**Clinical Pearl / High-Yield Fact**
In patients with suspected pulmonary hypertension, a right heart catheterization is essential to confirm the diagnosis and guide management.

**Correct Answer:** C. Right heart catheterization to confirm the diagnosis of pulmonary hypertension and guide management.

✓ Correct Answer: D. Echocardiogram