Fig. 1. Typical recordings of intracellular Ca2+measurements in one cell obtained by the 405:480-nm wavelength ratio during control conditions (top ) and after an infusion of 10−5M propofol (bottom ). Different 405:480-nm wavelength ratios are defined: the diastolic ratio, the systolic ratio, and the Ca2+transient (Δ ratio), which is the difference between the systolic and the diastolic value of the 405:480 nm ratio. (Top ) Drest= diastolic ratio after a long pause; ΔR1 =Δ ratio of the first beat after a long pause, D2–5and ΔR2–5= diastolic ratio and Δ ratio of beats 2 through 5. (Bottom ) Analysis of the slope of the decrease of intracellular Ca2+. This analysis was performed by measurement of the 405:480 ratio 120, 240, 360, and 480 ms after the peak of systolic Ca2+, as indicated by the arrows showing the corresponding time points in the S1beat. (Insert ) The superimposition of S1transients obtained during control condition (C) and during propofol infusion (P), showing a slower decrease in Ca2+transient after its peak during propofol infusion.