This is an example of mild mitral stenosis which is most commonly due to rheumatic heart disease.
The first heart sound is increased in intensity due to mild thickening of the the mitral valve leaflets.
The second heart sound is normal and unsplit
Systole is silent.
There is an opening snap 100 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.
In the animation you can see the turbulent blood flow from the left atrium into the left ventricle. You can see the minimally thickened mitral valve leaflets and the minimally enlarged left atrium. The excursion of the mitral valve leaflets is minimally decreased.