Images are from wildtype (A-C), early HF (D-I), acute HF (J-L), and chronic HF (M-O) mice. vWF staining is present within endocardial cells (within presumptive Weibel-Palade bodies) in all groups and very prominently in early HF (D, F, inset, arrows). Fibrin staining is limited on the endocardial surface of wildtype mice (B) but increased in HF mice (E, H, K, N). Small thrombi positive for both fibrin and vWF are present on the endocardial surface in both acute and chronic HF. vWF staining is limited on the endocardial surface in chronic HF mice (M-O). Note the heterogeneity in muscle fiber size in HF mice (I, O). Scale bar in O is 145 μm for all panels, except inset (84 μm).