Mastering Medical
USMLE Step 1 · Cardiovascular

Tricuspid regurgitation vs Pulmonary regurgitation

How to tell Tricuspid regurgitation and Pulmonary regurgitation apart when a board question makes them look alike.

Fastest separator

Tricuspid regurgitation is holosystolic at the lower left sternal border; pulmonary regurgitation is early diastolic at the left upper sternal border.

Side by side

Tricuspid regurgitationPulmonary regurgitation
Key clue

Holosystolic murmur at lower left sternal border that increases with inspiration, often from right-sided dilation or endocarditis.

Early diastolic decrescendo murmur at left upper sternal border, often from pulmonary hypertension.

Mechanism

Systolic RV-to-RA backflow causes venous congestion and a right-sided holosystolic murmur.

Diastolic pulmonary artery-to-RV backflow causes RV volume overload.

Labs and tests

Tricuspid regurgitation: holosystolic murmur at the lower left sternal border, louder on inspiration (Carvallo sign), with elevated JVP and prominent v wave, pulsatile tender hepatomegaly, and dependent edema. Common causes: right ventricular dilation from left-heart failure or pulmonary hypertension, IV drug use endocarditis, carcinoid heart disease, Ebstein anomaly.

Pulmonary regurgitation: early decrescendo diastolic murmur at the left upper sternal border (Graham Steell murmur when associated with severe pulmonary hypertension), often softer and harder to hear than aortic regurgitation. Common causes: pulmonary hypertension dilating the pulmonic annulus, prior repaired tetralogy of Fallot, infective endocarditis in IV drug users.

The trap

Both are right-sided murmurs and can increase with inspiration, so timing is the fastest separator.

Watch it explained

In the rapid reviewHeart Murmurs Made Easy: AS, MR, MVP & More for USMLE Step 1
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The repair move

For right-sided regurgitation, inspiration localizes right side, but systole versus diastole names the valve lesion.

Try a free question

Core

A patient with right-sided infective endocarditis has a high-pitched holosystolic murmur at the lower left sternal border that gets louder with inspiration. Which lesion is most likely?

Show answer and explanation

Answer: A. Tricuspid regurgitation. Tricuspid regurgitation is holosystolic at the lower left sternal border and increases with inspiration.

Why the other choices are tempting

  • B. Pulmonary regurgitation is an early diastolic decrescendo murmur, often related to pulmonary hypertension.
  • C. Mitral regurgitation is holosystolic at the apex with axillary radiation.
  • D. Aortic regurgitation is early diastolic along the left sternal border with wide pulse pressure.
  • E. VSD is holosystolic but is usually harsh and not the right-sided endocarditis/inspiration clue.

Flashcards

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What is the fastest separator for Tricuspid regurgitation vs Pulmonary regurgitation?

Tricuspid regurgitation is holosystolic at the lower left sternal border; pulmonary regurgitation is early diastolic at the left upper sternal border.

What clue should make you choose Tricuspid regurgitation?

Holosystolic murmur at lower left sternal border that increases with inspiration, often from right-sided dilation or endocarditis.

Quick answers

What is the fastest way to tell Tricuspid regurgitation from Pulmonary regurgitation?

Tricuspid regurgitation is holosystolic at the lower left sternal border; pulmonary regurgitation is early diastolic at the left upper sternal border.

What is the key clue for Tricuspid regurgitation?

Holosystolic murmur at lower left sternal border that increases with inspiration, often from right-sided dilation or endocarditis.

What is the key clue for Pulmonary regurgitation?

Early diastolic decrescendo murmur at left upper sternal border, often from pulmonary hypertension.

What is the common trap with Tricuspid regurgitation vs Pulmonary regurgitation?

Both are right-sided murmurs and can increase with inspiration, so timing is the fastest separator.