This is an example of moderate mitral stenosis which is most commonly due to rheumatic heart disease.
The first heart sound is increased in intensity due to moderate thickening of the the mitral valve leaflets.
The second heart sound is normal and unsplit
Systole is silent.
There is an opening snap 75 milliseconds into diastole. As mitral stenosis becomes more severe the opening snap will occur earlier in diastole.
The opening snap is followed by a diamond shaped low frequency murmur. Use the bell of the stethoscope to hear this murmur.
There is a second murmur in late diastole due to contraction of the left atrium.
In the animation you can see the turbulent blood flow from the left atrium into the left ventricle. You can see the moderately thickened mitral valve leaflets and the moderately enlarged left atrium. The excursion of the mitral valve leaflets is moderately decreased.