Prevention of Postoperative Atrial Fibrillation (POAF) Using Intra-Pericardial Amiodarone

Inclusion Criteria: * Subject aged 20-85 years old. * Patients able to provide written informed consent, understand, and be willing to comply with study-related procedures. * Participants who are scheduled to undergo open-chest cardiac surgery via complete median sternotomy. Includes: * Coronary artery bypass graft (CABG) and/or valve repair/replacement procedures (aortic, mitral, or tricuspid) * Isolated ascending aortic aneurysm replacement/repair * Note: Left atrial appendage (LAA) procedures are allowed if CABG and/or valve repair or replacement is the qualifying surgical procedure, but is not a qualifying surgical procedure on its own. * In sinus rhythm at the time of office visit and prior electrocardiogram (EKG) (note: continuous EKG monitoring for 48 hours is not required). Exclusion Criteria: * Subject unable to give voluntary written informed consent, is unlikely to cooperate or is legally incompetent, including subjects who are institutionalized by court or official order, or in a dependency relationship with, testing center or investigator. * Any condition which could interfere with the subject's ability to comply with the study. * Ongoing participation in an interventional clinical study or during the preceding 30 days. * Female subjects who are pregnant, breastfeeding, were pregnant within the last three months, or are planning to become pregnant during the course of the study. * Active skin or deep infection at the site of implantation. * History of chronic wounds or wound-healing disorders. * Known connective tissue diseases (e.g. Ehlers-Danlos syndrome, Epidermolysis bullosa, Marfan syndrome, Osteogenesis imperfecta). * Immune-suppressed subjects, immune-deficiency subjects (properly managed diabetes mellitus is not an exclusion criterion). * Concomitant oral or IV systemic corticosteroid therapy and/or other constant anti-inflammatory therapies. * Patients already receiving amiodarone as a treatment for atrial fibrillation or ventricular arrhythmias. * Disease of the left pleura, previous intervention in the left pleural space, or chest deformity. * Subjects with end-stage chronic-renal disease / dialysis. * STS (Society of Thoracic Surgeons Score) risk score \>5.5% for 30 day mortality.