 The purpose of this study is to see if a drug called lidocaine prevents cognitive injury a decline in mental abilities after heart surgery. Lidocaine is currently FDA approved and is commonly used for treating some heart rhythm disorders and for regional anesthesia blocking nerves. The investigators are enrolling subjects in this research project to see if lidocaine will reduce the high incidence of cognitive injury seen after heart surgery. As part of this study, the investigators will also evaluate the relationship between cognitive injury and genetic makeup and the chemical changes in the subjects blood during and after surgery. 