Intravenous Thyroxine for Heart-Eligible Organ Donors

Inclusion Criteria: * Declared dead by neurologic criteria (brain dead) * Authorization for organ donation and research * On one or more vasopressors and/or inotropes Exclusion Criteria: * Brain death declared more than 24 hours prior * Only vasopressor is vasopressin * Weight \< 45 kg (100 lbs) * Known coronary artery disease or history of myocardial infarction * Known valvular heart disease * Prior sternotomy or cardiac surgery * Donor at VA hospital * Received intravenous or oral thyroxine within past month * Known HIV+ status * Other reason donor is unable to receive study drug (determined by on-site personnel)