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Figure 1 Measurements of CFR

In Patient #1, the thermodilution curves constructed at baseline and during hyperemia nearly overlap. The averaged mean transit time is 0.23 s at baseline and 0.20 s during hyperemia, which is consistent with a severe decrease in CFR. In Patient #2, the duration of the hyperemic thermodilution curve (averaged mean transit time = 0.23 s) is significantly shorter than at baseline (averaged mean transit time = 1.01 s), which is consistent with a normal CFR. CFR = coronary flow reserve.