Study of T3 on the Incidence of Atrial Fibrillation in Patients Undergoing Cardiac Surgery

Inclusion Criteria: 1. Patients requiring CABG or valve repair/replacement surgery. 2. Patient must be able to provide informed consent. Exclusion Criteria: 1. Patients less than 18 or over 85 years of age. 2. Patients less than 50kg or greater than 120kg. 3. Patients currently with endocrine disorders, excluding diabetes. 4. Patients currently with thyroid dysfunction (e.g., hyper- hyperthyroidism, goiter, Grave's disease), myxedema, or myxedema coma, even if treated. 5. Patients currently receiving thyroid replacement therapy. 6. Patients currently receiving Ketamine, levarterenol or dietary (non-food) iodine supplementation. 7. Patients who have received any investigational drugs within the previous one month or five half-lives of the drug. 8. Patients who are pregnant. Pregnancy testing will be done for women of child-bearing potential. 9. Patients currently in atrial fibrillation.