Classification of the long-QT syndrome based on discriminant analysis of T-wave morphology

  • J. J. Struijk
  • J. K. Kanters
  • M. P. Andersen
  • T. Hardahl
  • C. Graff
  • M. Christiansen
  • E. Toft
Original Article


The long QT syndrome (LQTS) is a genetic disorder, typically characterized by a prolonged QT interval in the ECG due to abnormal cardiac repolarization. LQTS may lead to syncopal episodes and sudden cardiac death. Various parameters based on T-wave morphology, as well as the QT interval itself have been shown to be useful discriminators, but no single ECG parameter has been sufficient to solve the diagnostic problem. In this study we present a method for discrimination among persons with a normal genotype and those with mutations in the KCNQ1 (KvLQT1 or LQT1) and KCNH2 (HERG or LQT2) genes on the basis of parameters describing T-wave morphology in terms of duration, asymmetry, flatness and amplitude. Discriminant analyses based on 4 or 5 parameters both resulted in perfect discrimination in a learning set of 36 subjects. In both cases cross-validation of the resulting classifiers showed no misclassifications either.


Discriminant analysis ECG HERG KCNH2 KvLQT1 KCNQ1 Long QT syndrome T-wave 



We thank Knud Larsen for his help with the conversion of SCP files (Standard Communication Protocol) to MAT files (MatLab data format).


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Copyright information

© International Federation for Medical and Biological Engineering 2006

Authors and Affiliations

  • J. J. Struijk
    • 1
  • J. K. Kanters
    • 2
    • 3
    • 4
    • 6
  • M. P. Andersen
    • 1
  • T. Hardahl
    • 1
  • C. Graff
    • 1
  • M. Christiansen
    • 2
    • 5
  • E. Toft
    • 1
    • 6
  1. 1.Department of Health Science and TechnologyCenter for Sensory Motor Interaction (SMI)AalborgDenmark
  2. 2.Danish Arrhythmia Research Center (DARC)CopenhagenDenmark
  3. 3.Gentofte University HospitalCopenhagenDenmark
  4. 4.Laboratory of Experimental CardiologyUniversity of CopenhagenCopenhagenDenmark
  5. 5.Department of Clinical BiochemistryStatens SeruminstitutCopenhagenDenmark
  6. 6.Department of Cardiology, Aalborg HospitalÅrhus University HospitalsAalborgDenmark

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