title: Automated QT measurement and application to detection of moxifloxacin-induced changes.
abstract: BACKGROUND
  Concern for drug-induced QT prolongation has caused significant investment in QT measurement to safety-test new compounds. Manual methods are expensive and time-consuming. Reliable automatic methods would be highly desirable.
  
  
  METHODS
  Twelve-lead Holter recordings were annotated beat-to-beat by an automatic algorithm for global QRS onset and T offset. T offset was established from the time of peak T downslope plus a rate-dependent offset, analogous to the "tangent method," wherein T offset is determined by extrapolating the T downslope to an intersection with the baseline.
  
  
  CONCLUSIONS
  Variances of the beat-to-beat QT measurements were in the range 2.5-3.4 ms over three distinct databases, including a large heart failure database. Application to a moxifloxacin/placebo control database of 29 subjects showed excellent results.
authors.affiliation: Mortara Instrument, Milwaukee, WI, USA. David.Mortara@mortara.com
authors.forename: David W
authors.initials: DW
authors.lastname: Mortara
mesh_terms: D000465:Algorithms; D001372:Aza Compounds / Q000494:pharmacology*; D015716:Electrocardiography, Ambulatory / Q000187:drug effects; D005260:Female; D024841:Fluoroquinolones; D006333:Heart Failure / Q000503:physiopathology; D006801:Humans; D008133:Long QT Syndrome / Q000175:diagnosis; D008297:Male; D000077266:Moxifloxacin; D011804:Quinolines / Q000494:pharmacology*; D012815:Signal Processing, Computer-Assisted
chemical_list: D001372:Aza Compounds; D024841:Fluoroquinolones; D011804:Quinolines; D000077266:Moxifloxacin