I received a letter saying my echocardiogram is satisfactory with mild to moderate eccentric m.r through the cleft in left a.vsurgical repaired avsd?

Wording is strange: I guess you are questioning the word 'satisfactory' in this instance. Folks with that repair often have mitral regurgitation (mr) because the mitral valve is pretty abnormal at birth. Surgery rarely makes all of it go away. So 'mild' isn't bad. Mild/moderate a little more of a concern but usually well tolerated. If the left ventricle is normal sized and you feel well, leave it alone. Follow up.