A 55-year-old morbidly obese male is seen in the office for routine examination. He has a history of pulmonary hypertension and cor pulmonale. Examination reveals a palpable jugular venous pulse along with a systolic flow murmur on the right side of the sternum. Which of the following is the most likely diagnosis?

• A. Mitral insufficiency
• B. Tricuspid insufficiency
• C. Hepatic vein thrombosis
• D. Aneurysm of the thoracic aorta

Answer: (B)

When the right side of the heart is under chronic pressure from pulmonary hypertension, the tricuspid valve often becomes incompetent because the tricuspid annulus dilates as the right ventricle enlarges. This functional tricuspid regurgitation produces a systolic murmur that is best felt along the lower left sternal border and is typically accompanied by signs of elevated right-sided pressures, such as a palpable jugular venous pulse. In this scenario, the history of pulmonary hypertension with cor pulmonale plus a notable JVP and a systolic murmur along the sternum fits tricuspid insufficiency most closely.

Mitral insufficiency would present with an apical holosystolic murmur radiating to the axilla, not a right sternal border murmur with high JVP. Hepatic vein thrombosis (Budd-Chiari) mainly causes hepatomegaly, ascites, and abdominal pain without a systolic murmur at the sternum. An aneurysm of the thoracic aorta would typically have a different clinical picture, possibly a chest bruit or pulse disparities, but not the combination of right-sided failure signs with a right-sided systolic murmur due to tricuspid regurgitation.