Diastolic murmur:

The murmur of Mitral Stenosis is mid-diastolic and progresses with the severity from a short decresendo murmur to a longer cresendo murmur. In more severe cases, the murmur will stretch towards the second heart sound. In the early stage, the murmur may be only grade 1 or 2. The murmur is best heard at the apex of the heart with the patient in left lateral position. Rapid deep inspirations or mild exercise will augment the intensity.

Loud first heart sound:

An important sign in most patients with Mitral Stenosis is a loud first heart sound. This is often regarded as one of the best indicators of early stage MS. Elevated atrial pressure forces the Mitral Valve open widely and will close with a more rapid motion.  The amplitude of S1 will not vary as the severity increases, however, in severe cases, the Mitral Valve may be calcified to such a degree that movement is inhibited and S1 becomes very soft.

Opening Snap:

Tension in the mitral leaflets and delayed opening of the valve causes a high frequency opening snap in early diastole. The timing of the opening snap is important as it indicates the severity of the lesion. In the early stage the timing is about 0,09 to 0,13 sec after the aortic component of S2. As left atrial pressure increases, in severe cases this interval may be as short as 0.04 to 0.05 seconds.