Electrocardiogram of lead V1. (A) Electrocardiogram of patient 10577-1 with a TpTe interval of 83 ms or a TpTe/QT ratio of 0.22 and a history of VF. (B) Electrocardiogram of patient 10568-1 with a TpTe interval of 69 ms or a TpTe/QT ratio of 0.18, a mutation in the SCN5A gene and who is asymptomatic. (C) Electrocardiogram of patient 10399-1 with a TpTe interval of 55 ms or a TpTe/QT ratio of 0.17 and no history of cardiac events. The continuous line represents the end of the T-wave, the dashed line the peak of the T-wave in the patients without any cardiac events. The dotted line shows the peak of the T-wave of the patient who had VF.