TpeakTend interval in long QT syndrome

Background: The TpeakTend (TpTe) interval is believed to reflect the transmural dispersion of repolarization. Accordingly, it should be a risk factor in long QT syndrome (LQTS). The aim of the study was to determine the effect of genotype on TpTe interval and test whether it was related to the occurrence of syncope. Methods: Electrocardiograms were taken in 95 patients with LQTS drawn from the Danish long QT registry (44 patients with KvLQT1, 43 with HERG, and 8 with SCN5A mutations) and manually evaluated for the QT, QT(peak), and RR interval. Results and conclusion: (1) TpTe cannot be used to distinguish symptomatic from asymptomatic patients with LQTS; (2) HERG patients have longer TpTe than KvLQT1 patients; and (3) there is no need to heart rate-correct TpTe intervals in patients with LQTS. (C) 2008 Elsevier Inc. All rights reserved.