Figure 7-19 Percent segment shortening (%SS) in the intermittently ischemic and reperfused left anterior descending coronary artery (LAD) region. The %SS decreases significantly (P < .05) from baseline during each 5-minute LAD occlusion and reperfusion in all groups. Significant decreases in %SS during each 5-minute reperfusion and throughout 180 minutes of final reperfusion are observed in dogs pretreated with glyburide, a K_ATP channel antagonist, in the presence or absence of isoflurane. The %SS recovers to baseline values after reperfusion in dogs receiving isoflurane alone. †, Significantly (P < .05) different from dogs pretreated with drug vehicle; §, significantly (P < .05) different from dogs pretreated with glyburide; ‡, significantly (P < .05) different from dogs receiving glyburide and isoflurane. (From Kersten JR, Schmeling TJ, Hettrick DA, et al: Mechanism of cardioprotection by isoflurane: Role of adenosine triphosphate-regulated potassium (KATP) channels. Anesthesiology 85:794–807, 1996.)