1. Ten full-term neonates (> 36 week gestation), between 1-30 days of age, who present for arterial switch operation or Norwood operation will have 2 ml of blood drawn prior to cardiac surgery, 2 ml blood drawn each day after cardiac surgery as long as the patient remains in the intensive care unit with indwelling lines (maximum of 5 days) and 2 ml blood drawn on the day of the followup brain magnetic resonance imaging study (if not within the maximum of 5 days) to determine blood concentrations S100B and NSE.