Eccentric hypertrophy is from volume overload (AR, HF) as opposed to concentric hypertrophy which is from increased afterload (AS, HTN)
Dilated Cardiomyopathy is a classfication of cardiomyopathy. As far as I know, a lot of it is idiopathic, but you can also have something like adriamycin-induced CM or myocarditis leading to DCM. There's also Hypertrophic (classic one is asymmetric with thickening of interventricular septum, but you can have thickening of the free wall too), Restrictive, Ischemic...