Assessment of Intra-Operative Atrial Fibrillation Inducibility As a Screening Tool to Prevent Post-Operative Atrial Fibrillation With Prophylaxis Amiodarone

In the operating room, as part of the open heart surgery, the surgeon will stimulate the superior right atrium section of the heart with a pacemaker for 30 seconds just prior to starting the heart and lung bypass machine. The stimulation is done to see how sensitive the heart is to developing atrial fibrillation. This test result will be documented. The procedure will only take 60 seconds out of the entire operation. It does not involve taking any samples of tissue or blood. Following this step, if the heart demonstrates atrial fibrillation for at least 30 seconds then the participant will then be randomized to either receive the prophylactic drug treatment using Amiodarone or to no prophylactic drug administration. The participant has a 50% chance of receiving the FDA approved study drug Amiodarone. The study arms consist of prophylactic drug administration with Amiodarone, No prophylactic drug administration, or no atrial fibrillation reaction after stimulation with the pacemaker. The remainder of the surgical procedure will not be affected, and will follow routine surgical practice.