A high-pitched murmur radiating to the left axilla most likely indicates which valvular lesion?

A high-pitched murmur radiating to the left axilla most likely indicates which valvular lesion?

• A. Aortic Regurgitation
• B. Mitral Regurgitation
• C. Pulmonic Stenosis
• D. Tricuspid Regurgitation

Answer: (B)

This question tests how auscultation findings map to valve lesions, specifically how murmur characteristics tell you which valve is involved. A mitral regurgitation murmur is holosystolic, high-pitched, and blowing, heard best at the cardiac apex (the left 5th intercostal space at the midclavicular line) and classically radiates to the left axilla. The radiation to the axilla happens because the regurgitant jet moves from the left ventricle into the left atrium during systole, directing sound toward the posteromedial chest and axillary region. This pattern differentiates it from other valvular murmurs: aortic regurgitation is a diastolic decrescendo murmur best heard along the left sternal border, pulmonic stenosis is a systolic ejection murmur at the left upper sternal border, and tricuspid regurgitation is a holosystolic murmur at the left lower sternal border, often louder with inspiration. So the described high-pitched murmur radiating to the left axilla most strongly points to mitral regurgitation.

This question tests how auscultation findings map to valve lesions, specifically how murmur characteristics tell you which valve is involved. A mitral regurgitation murmur is holosystolic, high-pitched, and blowing, heard best at the cardiac apex (the left 5th intercostal space at the midclavicular line) and classically radiates to the left axilla. The radiation to the axilla happens because the regurgitant jet moves from the left ventricle into the left atrium during systole, directing sound toward the posteromedial chest and axillary region. This pattern differentiates it from other valvular murmurs: aortic regurgitation is a diastolic decrescendo murmur best heard along the left sternal border, pulmonic stenosis is a systolic ejection murmur at the left upper sternal border, and tricuspid regurgitation is a holosystolic murmur at the left lower sternal border, often louder with inspiration. So the described high-pitched murmur radiating to the left axilla most strongly points to mitral regurgitation.