A soft high-pitched blowing diastolic murmur along the left sternal border heard with the patient seated and leaning forward after exhaling is characteristic of which condition?

• A. Mitral Stenosis
• B. Pulmonary Regurgitation
• C. Aortic Stenosis
• D. Aortic Regurgitation

Answer: (D)

Main idea: the timing, quality, and maneuver used to auscultate a diastolic murmur point to aortic regurgitation. This is a diastolic, high-pitched blowing murmur with a decrescendo shape heard best along the left sternal border. The maneuver—having the patient sit up and lean forward after exhaling—brings the aortic valve closer to the chest wall and accentuates regurgitant flow, making the murmur clearer.

In aortic regurgitation, blood leaks backward from the aorta into the left ventricle during diastole, producing that diastolic decrescendo murmur. The left sternal border location corresponds to the aortic valve area when the chest is examined; leaning forward after expiration specifically enhances this murmur.

This differs from mitral stenosis, which is a diastolic rumble heard best at the apex; from aortic stenosis, which is a systolic murmur heard best at the right upper sternal border; and from pulmonary regurgitation, which is also diastolic but typically heard at the left upper sternal border and often in the setting of pulmonary hypertension.