Which auscultatory finding is characteristic of mitral stenosis?

• A. Diastolic rumble with opening snap and loud S1
• B. Systolic murmur with radiation to carotids
• C. Continuous murmur
• D. Ejection murmur

Answer: (A)

Mitral stenosis is characterized by a diastolic murmur produced by turbulent flow across a narrowed mitral valve. The hallmark auditory finding is a low-pitched diastolic rumble heard best at the apex with the patient in the left lateral decubitus position. This rumble typically begins after an opening snap, which follows S2 and results from the sudden tensing of the stenotic mitral leaflets as they finally open in early diastole. The first heart sound is often loud because the thickened valve leaflets snap shut against a high left atrial pressure. The murmur can become louder with expiration and may show presystolic accentuation just before S1 of the next beat due to atrial contraction filling a stiff ventricle. These features together are distinctive for mitral stenosis, whereas a systolic murmur radiating to the carotids suggests aortic stenosis, a continuous murmur points to a PDA, and an ejection-type murmur is not typical of MS.