Devices, systems, and methods for accessing tissue, including the internal and external tissues of the heart, are disclosed. At least some of the embodiments disclosed herein provide access to the external surface of the heart through the pericardial space for localized delivery of leads to the heart tissue. At least some of the embodiments disclosed herein provide access to the pericardial space for removal of accumulated fluid. In addition, various disclosed embodiments provide devices, systems, and methods for engaging a tissue, for removing fluid from a space within a body, and for the delivery of substances to a targeted site for therapeutic purposes.
