Hey guys!

So I am a little into my CV class and clinical and was presented with this information:
1) AV valve (Tricuspid or MV) Stenosis reduces SV by decreasing ventricular preload
2) Semilunar valve (Pulmonary or AV) stenosis reduces SV primarily by increasing afterload

My question/issue is that I cannot find cut and dry info anywhere. I would think that AV stenosis would cause decreased afterload d/t a "tight" valve and elevated turbulence in the ventricles?

And the semilunar valve stenosis would cause the same thing but in the pulmonary artery and aorta?

I understand that AV stenosis would cause increased atrial pressure and probably hypertrophy only d/t the stenosed valve leading to lower ventricle pressure because of decreased atrial volume and increased turbulence and the same with semilunar stenosis leading to decreased pulmonary and aorta diastolic pressure. Or am I completely wrong on this?? Any help would be greatly appreciated!!!