The decrescendo–crescendo systolic murmur best heard at the base of the heart and radiating to the neck corresponds to which condition?

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

Answer: (A)

In systolic murmurs, the combination of where the sound is loudest and how it changes through systole helps identify the valve involved. Aortic stenosis creates a crescendo–decrescendo (midsystolic) murmur that is best heard at the right upper sternal border, near the base of the heart, and it frequently radiates to the neck through the carotid arteries. The narrowing makes blood flow accelerate as the ventricle pushes against the valve, producing the peak in the middle of systole and a fall-off toward the end, with the turbulent flow directed upward along the aorta toward the neck.

This pattern distinguishes it from other common murmurs: regurgitation in this timeframe is diastolic, not systolic; mitral stenosis is a diastolic rumble heard best at the apex; pulmonic stenosis is a systolic murmur at the left upper sternal border with less characteristic neck radiation.