Figure 1. Midazolam and alfentanil plasma concentrations during and after anesthesia in 15 patients having coronary artery bypass graft receiving placebo (left) and in 15 patients receiving diltiazem (right). A = induction of anesthesia; B = initiation of CPB (average); C = end of CPB (average); D = end of anesthesia (average); and E = end of diltiazem or placebo infusion.