The aim of the study is to evaluate coronary flow reserve (CFR), index of microcirculatory resistance (IMR), and proportion of overt microvascular disease, defined as depressed CFR as well as elevated IMR in patients with cardiac amyloidosis. The second objective of this study is to compare results of non-invasive test including serum light chain amount, Doppler echocardiography with 2D strain, and cardiac perfusion MRI. The third object of this study is to evaluate the association between physiologic indices and pathologically measured percent area involvement of interstitium.