This is a simulation of Myocarditis taken at the apex.
1. The first heart sound is softer than normal because of decreased function of the left ventricle.
2. The second heart sound is normal at the mitral area.
3. There is a third heart sound caused by the failure of the left ventricle.
4. A rectangular, medium-pitched murmur of mild mitral regurgitation is caused by the incomplete closure of the mitral valve leaflets.
In the anatomy tab you can see the enlarged left ventricle with decreased vigor of contraction.
You can see the regurgitant turbulent flow from the left ventricle into the left atrium which is responsible for the murmur.
Myocarditis is often the result of a viral infection of the myocardium.