In the failing myocardium a subendocardial plexus can develop. Detection of presence or function however of such a plexus does not form part of the present diagnostic spectrum for heart failure. This may change now new methods for high resolution imaging of myocardial perfusion distribution are being developed. A severely hypertrophic heart was harvested during transplantation and analyzed for morphology of the intramural coronary arterial vasculature. The heart only had one coronary ostium and the main branches of the coronary artery were cannulated. A fluorescent casting material was infused that was allowed to harden under physiological pressure. The entire heart was frozen and placed in a novel imaging cryomicrotome and sequentially cut in 25 μm slices. High resolution images of each cutting plane were acquired allowing detailed 3D reconstruction of the arterial vasculature. The epicardial layer of the free wall demonstrated a normal vasculature with penetrating vessels branching arteries. The endocardial layer and the septum revealed a highly interconnected vascular plexus, with large vessels oriented parallel to the apico-basal axis. An extensive endocardial network with collaterals was detected forming connections between the main epicardial branches. We conclude that outward remodeling of transmural vessels did not prevent the generation and growth of subendocardial conduit arteries. The orientation and vascular volume in the plexus provides an opportunity for detection by novel techniques of MRI contrast imaging currently developed. Knowledge of the effect on perfusion studies is required to prevent misinterpretation of subendocardial perfusion images in heart failure.