title: Minimal T-wave representation and its use in the assessment of drug arrhythmogenicity.
abstract: BACKGROUND
  Recently, numerous models and techniques have been developed for analyzing and extracting features from the T wave which could be used as biomarkers for drug-induced abnormalities. The majority of these techniques and algorithms use features that determine readily apparent characteristics of the T wave, such as duration, area, amplitude, and slopes.
  
  
  METHODS
  In the present work the T wave was down-sampled to a minimal rate, such that a good reconstruction was still possible. The entire T wave was then used as a feature vector to assess drug-induced repolarization effects. The ability of the samples or combinations of samples obtained from the minimal T-wave representation to correctly classify a group of subjects before and after receiving d,l-sotalol 160 mg and 320 mg was evaluated using a linear discriminant analysis (LDA).
  
  
  RESULTS
  The results showed that a combination of eight samples from the minimal T-wave representation can be used to identify normal from abnormal repolarization significantly better compared to the heart rate-corrected QT interval (QTc). It was further indicated that the interval from the peak of the T wave to the end of the T wave (Tpe) becomes relatively shorter after IKrinhibition by d,l-sotalol and that the most pronounced repolarization changes were present in the ascending segment of the minimal T-wave representation.
  
  
  CONCLUSIONS
  The minimal T-wave representation can potentially be used as a new tool to identify normal from abnormal repolarization in drug safety studies.
authors: Center for Sensory Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
authors: Saeed
authors: S
authors: Shakibfar
authors: Medical Informatics Group (MI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
authors: Claus
authors: C
authors: Graff
authors: Laboratory of Experimental Cardiology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.|Department of Cardiology, Herlev & Gentofte University Hospitals, Copenhagen, Denmark.|Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark.
authors: Jørgen K
authors: JK
authors: Kanters
authors: Center for Schizophrenia, Aalborg Psychiatric Hospital, Aalborg University Hospital, Aalborg, Denmark.
authors: Jimmi
authors: J
authors: Nielsen
authors: Medical Informatics Group (MI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
authors: Samuel
authors: S
authors: Schmidt
authors: Medical Informatics Group (MI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
authors: Johannes J
authors: JJ
authors: Struijk
mesh_terms: D000293:Adolescent; D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D004562:Electrocardiography / Q000187:drug effects* / Q000706:statistics & numerical data; D006321:Heart / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D013015:Sotalol / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D000889:Anti-Arrhythmia Agents; D013015:Sotalol
keywords: QT interval; T wave; Tpeak-Tend; electrocardiogram; repolarization