A diastolic decrescendo murmur heard at the right second intercostal space is most consistent with which diagnosis?

• A. Aortic regurgitation
• B. Mitral stenosis
• C. Aortic stenosis
• D. Pulmonary regurgitation

Answer: (A)

A diastolic decrescendo murmur signals regurgitant flow during diastole. When this murmur is heard at the right second intercostal space, you’re over the aortic valve area. Leaking back from the aorta into the left ventricle in diastole produces this early-to-mid diastolic decrescendo pattern, which is classic for aortic regurgitation.

Mitral stenosis would present as a diastolic rumble at the cardiac apex, not at the aortic area. Aortic stenosis produces a systolic, crescendo–decrescendo murmur best heard at the right second intercostal space and radiating to the carotids. Pulmonary regurgitation causes a diastolic decrescendo murmur best heard at the left upper sternal border, not the right aortic area.