within the chest. For example, patients who have undergone Fontan palliation have only 1 atrioventricular valve, and a capacitance chamber must be constructed to adequately connect the TAH-t. Virtual implantation offers the ability to test several surgical approaches for device placement before the patient even enters the operating room. This study was limited by a single-center experience in a small patient cohort. In addition, the assessment by virtual implantation was retrospective, and no 50cc TAH-t device was actually implanted to confirm the predicted results of the virtual implantation because it was not available during the study. However, two 70cc TAH-t devices were placed successfully as predicted by virtual implantation. In conclusion, virtual compatibility testing allows device consideration for fit to be individualized and represents a movement away from using generalized assumptions about heart size, chest wall anatomy, and spatial relationships of cardiothoracic structures to determine fit. Disclosure statement