This is an example of moderate tricuspid 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 tricuspid valve leaflets.
The second heart sound is normal and unsplit.
Systole is silent.
There is a tricuspid opening snap 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 right atrium.
In the animation you can see the turbulent blood flow from the right atrium into the right ventricle. You can see the moderately thickened tricuspid valve leaflets and the moderately enlarged right atrium. The excursion of the tricuspid valve leaflets is moderately decreased.
For this condition the murmur intensity and tricuspid opening snap increase with inspiration.