Abstract: Disclosed herein are ex-vivo cardiac perfusion systems that can support the metabolic function of an ex-vivo heart and also have the capacity to test the functions of the heart. For example, an ex-vivo heart can be placed within and connected to a cardiac perfusion system, as disclosed herein, resuscitated and supported medically, and also tested to determine cardiac recovery. Further, these systems can also be used for research purposes to study the pressure, work, and mechanical function of many types of hearts (e.g., failed hearts that are explanted at the time of heart transplant). Some embodiments include a detachable sub-system that includes a heart chamber and components for operating in a Langendorff mode while transporting an ex-vivo heart, and the sub-system can be coupled to a differential perfusion system to form a larger, full service system for supporting, recovering, testing the heart.