Randomization The investigator will use NQuery software (Statistical Solutions Ltd., Boston, MA) to create a randomization scheme stratified by the three types of elective surgery: CABG, aortic valve replacement, and CABG plus aortic valve replacement. Patients will be randomized in a 1:1 ratio to receive either SGB (case, injection of 10 mL 0.5% bupivacaine injection) or sham SGB (control, injection of 10 mL 0.9% saline). For each of the three surgery types, treatment assignments will be placed in opaque envelopes, numbered sequentially; these three series of assignments will be maintained in separate surgery-specific boxes. Medications will be unidentified at the time of injection and the anesthesiologists and cardiac surgeons will be blinded to sham versus treatment group.