T(peak)T(end) interval in long QT syndrome.
BACKGROUND
The T(peak)T(end) (T(p)T(e)) 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 T(p)T(e) 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.


CONCLUSIONS
(1) T(p)T(e) cannot be used to distinguish symptomatic from asymptomatic patients with LQTS; (2) HERG patients have longer T(p)T(e) than KvLQT1 patients; and (3) there is no need to heart rate-correct T(p)T(e) intervals in patients with LQTS.
Kanters
Jorgen K
JK
Danish National Research Foundation Center of Arrhythmias (DARC), Copenhagen, Denmark.
Haarmark
Christian
C
Vedel-Larsen
Esben
E
Andersen
Mads P
MP
Graff
Claus
C
Struijk
Johannes J
JJ
Thomsen
Poul Erik Bloch
PE
Christiansen
Michael
M
Jensen
Henrik K
HK
Toft
Egon
E
D000328:Adult; D015897:Comorbidity; D003718:Denmark / Q000453:epidemiology; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000379:methods* / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013575:Syncope / Q000175:diagnosis* / Q000453:epidemiology*