A blowing, musical murmur along the left sternal border is most consistent with which valve lesion?

• A. Mitral regurgitation
• B. Tricuspid regurgitation
• C. Aortic stenosis
• D. Pulmonic regurgitation

Answer: (B)

A blowing, musical murmur heard along the left lower sternal border points to regurgitant flow through the valve on the right side of the heart. This pattern is classic for tricuspid regurgitation, where blood leaks backward from the right ventricle into the right atrium during systole. The murmur is typically holosystolic and best heard at the left lower sternal border, and it often becomes louder with inspiration. In contrast, mitral regurgitation is best heard at the apex and radiates to the axilla, aortic stenosis is a harsh systolic murmur at the right upper sternal border, and pulmonic regurgitation is a diastolic murmur to the left upper sternal border. Thus, the described murmur most fits tricuspid regurgitation.