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Figure 4 Comparison of the differences before and after epinephrine in the mean QTc-e (A), QTc-p (B), Tcp-e (C), and Tcp-e/QTc-e ratio (D), which were averaged among 87-leads, in LQT1, LQT2, and control groups. The changes in the mean QTc-e with epinephrine were largest in LQT1 patients, intermediate in LQT2 patients, and were not significant in control patients (A), whereas changes in the mean QTc-p were not different among the three groups (B). As a consequence, the changes in the Tcp-e (C) and Tcp-e/QTc-e ratio (D) were largest in LQT1 patients, intermediate in LQT2 patients, and were not significant in control patients.