Nineteen (19) patients with life-threatening, biventricular failure who are not eligible for cardiac transplant will be enrolled in the Primary Arm of the study and followed for up to six months post-TAH-t implant. Safety will be evaluated by reviewing the adverse events that are experienced by the enrolled subjects and comparing them to previous experience of TAH-t patients who were waiting for a heart transplant. Since approximately 74% of patients with this condition would not be expected to live beyond six months, the benefit of the TAH-t for DT will be confirmed based on survival to six months without experiencing permanent disabling stroke-related deficits. After the six month follow-up visit, patients will continue to be followed under the study for up to five (5) years postTAH-t implant [every six months for up to two years while supported with the TAH-t implant and then annually for another three years].