Identification of concealed and manifest long QT syndrome using a novel T wave analysis program

Alan Sugrue, Peter Noseworthy, Vaclav Kremen, J. Martijn Bos, Bo Qiang, Ram K. Rohatgi, Yehu Sapir, Zachi I. Attia, Peter Brady, Samuel J Asirvatham, Paul Andrew Friedman, Michael John Ackerman

Research output: Contribution to journalArticle

8 Scopus citations


Background - Congenital long QT syndrome (LQTS) is characterized by QT prolongation. However, the QT interval itself is insufficient for diagnosis, unless the corrected QT interval is repeatedly ≥500 ms without an acquired explanation. Further, the majority of LQTS patients have a corrected QT interval below this threshold, and a significant minority has normal resting corrected QT interval values. Here, we aimed to develop and validate a novel, quantitative T wave morphological analysis program to differentiate LQTS patients from healthy controls. Methods and Results - We analyzed a genotyped cohort of 420 patients (22±16 years, 43% male) with either LQT1 (61%) or LQT2 (39%). ECG analysis was conducted using a novel, proprietary T wave analysis program that quantitates subtle changes in T wave morphology. The top 3 discriminating features in each ECG lead were determined and the lead with the best discrimination selected. Classification was performed using a linear discriminant classifier and validated on an untouched cohort. The top 3 features were Tpeak-Tend interval, T wave left slope, and T wave center of gravity x axis (last 25% of the T wave). Lead V6 had the best discrimination. It could distinguish 86.8% of LQTS patients from healthy controls. Moreover, it distinguished 83.33% of patients with concealed LQTS from controls, despite having essentially identical resting corrected QT interval values. Conclusions - T wave quantitative analysis on the 12-lead surface ECG provides an effective, novel tool to distinguish patients with either LQT1/LQT2 from healthy matched controls. It can provide guidance while mutation-specific genetic testing is in motion for family members.

Original languageEnglish (US)
JournalCirculation: Arrhythmia and Electrophysiology
Issue number7
StatePublished - Jul 1 2016



  • diagnosis
  • electrocardiography
  • long QT syndrome
  • sudden cardiac death
  • T wave analysis
  • ventricular repolarization

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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