The severity of VES in three-vessel diseased CABG patients is shown as VES events per hour during each time period. IP, ischemic preconditioning; T₁, from the preoperative day to the morning of operation; T₂, during IP protocol or 10 min of CPB before cross-clamping; T₃, 2 h after reperfusion; T₄, in the ICU, 2 h after reperfusion till first postoperative morning; T₅, in the ICU, from first to second postoperative morning. Data presented as mean±SEM. Significance of difference between the groups by Student's t-test, the symbol (**) represents P<0.01. Significance of difference between the groups by GLM analysis with repeated measures, the symbol (††) represents P<0.01.