Which statement accurately distinguishes stenosis from regurgitation?

• A. Stenosis narrows the valve causing a murmur during systole or diastole
• B. Regurgitation backward flow with holosystolic murmur (mitral) or early diastolic murmur (aortic)
• C. Stenosis produces a holosystolic murmur
• D. Regurgitation murmurs are diastolic

Answer: (B)

Understanding murmurs hinges on how valve problems alter blood flow and when that flow turbulence is heard. Stenosis narrows a valve opening, so the murmur reflects turbulent forward flow during the phase the valve should be opening. That means different valves produce different timing: aortic stenosis typically gives a systolic murmur, while mitral stenosis gives a diastolic murmur. Regurgitation is backward flow through a valve that isn’t closing properly, so the timing follows the backward flow: mitral regurgitation produces a holosystolic murmur because backward flow occurs throughout systole, and aortic regurgitation produces an early diastolic murmur as backflow occurs right after the aortic valve should have closed. The statement that regurgitation involves backward flow with a holosystolic murmur for the mitral valve or an early diastolic murmur for the aortic valve accurately captures this distinction. The other options mix timing or valve involvement in ways that don’t fit the typical patterns.