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Figure 3 Plots of the mean QT_e and mean QT_p values against the mean heart rate in 11 patients with LQT1 (open circles and squares) and 11 patients with LQT2 (solid circles and squares). In both groups of patients, the mean T_p-e value (mean QT_e – mean QT_p) after propranolol administration (P) was smaller than that at the baseline condition (B), even if the mean heart rate was slower after propranolol. The mean T_p-e value after epinephrine administration (E) was much greater than that at the baseline condition, even if the mean heart rate was faster after epinephrine in both groups. Moreover, the mean T_p-e value after epinephrine was larger in the LQT1 group than in the LQT2 group, even if the mean heart rate was faster in the LQT1 group.