What auscultatory features are typical of mitral stenosis?

• A. Opening snap followed by a decrescendo diastolic murmur
• B. Opening snap followed by a high-pitched diastolic murmur
• C. Systolic ejection murmur at the base
• D. Continuous murmur

Answer: (A)

Mitral stenosis classically produces an opening snap after S2 as the stiff, fused mitral leaflets suddenly separate, followed by a low-pitched, rumbling diastolic murmur that typically decrescendos as diastole progresses. This murmur is best heard at the apex with the patient in the left lateral decubitus position, often louder with expiration, and may be accompanied by presystolic accentuation in more severe disease. The sequence—opening snap then a decrescendo diastolic murmur—is the hallmark of mitral stenosis. The other descriptions point to different problems: a systolic ejection murmur at the base suggests aortic stenosis, a continuous murmur suggests PDA, and a high-pitched diastolic murmur is not characteristic of mitral stenosis.