title: Risk assessment of ventricular arrhythmia using new parameters based on high resolution body surface potential mapping.
abstract: BACKGROUND
  The effective screening of myocardial infarction (MI) patients threatened by ventricular tachycardia (VT) is an important issue in clinical practice, especially in the process of implantable cardioverter-defibrillator (ICD) therapy recommendation. This study proposes new parameters describing depolarization and repolarization inhomogeneity in high resolution body surface potential maps (HR BSPM) to identify MI patients threatened by VT.
  
  
  METHODS
  High resolution ECGs were recorded from 64 surface leads. Time-averaged HR BSPMs were used. Several parameters for arrhythmia risk assessment were calculated in 2 groups of MI patients: those with and without documented VT. Additionally, a control group of healthy subjects was studied. To assess the risk of VT, the following parameters were proposed: correlation coefficient between STT and QRST integral maps (STT_QRST_CORR), departure index of absolute value of STT integral map (STT_DI), and departure index of absolute value of T-wave shape index (TSI_DI). These new parameters were compared to known parameters: QRS width, QT interval, QT dispersion, Tpeak-Tend interval, total cosines between QRS complex and T wave, and non-dipolar content of QRST integral maps.
  
  
  RESULTS
  STT_DI, TSI_DI, STT_QRST_CORR, QRS width, and QT interval parameters were statistically significant (p ≤ 0.05) in arrhythmia risk assessment. The highest sensitivity was found for the STT_DI parameter (0.77) and the highest specificity for TSI_DI (0.79).
  
  
  CONCLUSIONS
  Arrhythmia risk is demonstrated by both abnormal spatial distribution of the repolarization phase and changed relationship between depolarization and repolarization phases, as well as their prolongation. The proposed new parameters might be applied for risk stratification of cardiac arrhythmia.
authors.affiliation: Nalecz Institute of Biocybernetics and Biomedical Engineering PAS, Warsaw, Poland.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Fereniec
authors.forename: Gunter
authors.initials: G
authors.lastname: Stix
authors.forename: Michal
authors.initials: M
authors.lastname: Kania
authors.forename: Tomasz
authors.initials: T
authors.lastname: Mroczka
authors.forename: Dariusz
authors.initials: D
authors.lastname: Janusek
authors.forename: Roman
authors.initials: R
authors.lastname: Maniewski
mesh_terms: D000368:Aged; D018780:Body Surface Potential Mapping / Q000379:methods*; D004562:Electrocardiography; D006801:Humans; D008875:Middle Aged; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014463:Ultrasonography