A Study of Stellate Ganglion Block for Prevention of Atrial Fibrillation

Inclusion Criteria: * Patient presenting for cardiac surgery at the Mayo Clinic in Rochester, Minnesota. * Patients scheduled to undergo mitral or aortic valve surgery with or without coronary artery bypass grafting. Exclusion Criteria: * Patients with a history of permanent atrial fibrillation, left or right ventricular assist device implantation or explantation. * Patients with procedures not requiring cardiopulmonary bypass. * Patients with procedures requiring deep hypothermic circulatory arrest. * Patients with active infection or sepsis. * Pre-operative immunosuppressive medication use (including steroid use). * Pre-operative anti-arrhythmic medication use (aside from beta-blockers). * Patients with Immunodeficiency syndrome. * Patients with known neurologic disorder. * Patients requiring left internal jugular central line placement. * Performance of Maze procedures or left atrial appendage ligation procedures will not exclude patients from potential enrollment as atrial fibrillation still occurs postoperatively while the scarring from the Maze procedure forms.