Figure 2. The parameters of ST segment deviation on Holter electrocardiographic data for preoperative (Preop), pre-cardiopulmonary bypass (Pre-CPB), CPB, post-CPB, postoperative (Postop), total intraoperative (Intraop), and all combined (All) periods are presented. The percentages or means +/- SD of each parameter are presented separately for ST segment depression (ST [arrow down]) and ST segment elevation (ST [arrow up]) episodes. Sometimes the means for the two groups are so close that their graphic displays overlap. A and B present data for episodes starting in the respective periods. B to D present means +/- SD per hour of interpretable data for each perioperative period only for patients who had ST segment deviation in that period. AUC = area under the curve, i.e., ST segment deviation-duration integral (mm [center dot] min); HR = heart rate (beats/min). *P less or equal to 0.05 with respect to the preoperative ST segment deviation of the same type (depression or elevation).