Syncardia 50cc TAH-t as a Bridge to Transplant

The primary objective of the study is to evaluate whether the 50cc TAH-t can safely support, and provide probable benefit to, transplant-eligible pediatric patients (aged 10 - 18 years) and can safely and effectively support transplant-eligible adult patients (aged 19 - 75 years) at imminent risk of death from biventricular failure without experiencing permanent disabling, stroke-related deficits. The study will be conducted as a three-arm trial of the 50cc temporary Total Artificial Heart (TAH-t) as a bridge to transplant: * The Primary Pediatric Arm of the trial will evaluate the safety and probable benefit of the 50cc TAH-t for transplant-eligible patients 10 through 18 years of age. * The Primary Adult Arm of the trial will evaluate the safety and efficacy of the 50cc TAH-t for transplant-eligible patients 19 through 75 years of age. * The Secondary Arm will capture pediatric and adult subjects who did not meet enrollment criteria for a Primary Arm, but meet the less restrictive Secondary Arm enrollment criteria, in order to further characterize the use of the device.