Typical Daily Experiences, Ischemia and Repolarization in Coronary Artery Disease

CAD is the most common setting in which sudden cardiac death (SCD) occurs. SCD is the leading cause of death in the U.S. In this study we propose to test the following in patients with CAD: * Determine whether experiences assessed randomly throughout the day are associated with changes in the blood supply to your heart muscle as measured by electrical recordings from your chest. * Determine whether typical daily experiences are associated with changes in the recovery time portion of your heart beat cycle as measured by electrical recordings from your chest. * Determine whether changes in the recovery time portion of your heart beat cycle associated with typical daily experiences occur exclusively with changes in the blood supply to your heart muscle. * Determine whether typical daily experiences influences blood supply and recovery time based on the severity and presence of CAD (when comparing CAD patients to healthy subjects).