title: Assessment of myocardial infarct size with body surface potential mapping: validation against contrast-enhanced cardiac magnetic resonance imaging.
abstract: BACKGROUND
  Assessment of myocardial infarct (MI) size is important for therapeutic and prognostic reasons. We used body surface potential mapping (BSPM) to evaluate whether single-lead electrocardiographic variables can assess MI size.
  
  
  METHODS
  We performed BSPM with 120 leads covering the front and back chest (plus limb leads) on 57 patients at different phases of MI: acutely, during healing, and in the chronic phase. Final MI size was determined by contrast-enhanced cardiac magnetic resonance imaging (DE-CMR) and correlated with various computed depolarization- and repolarization-phase BSPM variables. We also calculated correlations between BSPM variables and enzymatic MI size (peak CK-MBm).
  
  
  RESULTS
  BSPM variables reflecting the Q- and R wave showed strong correlations with MI size at all stages of MI. R width performed the best, showing its strongest correlation with MI size on the upper right back, there representing the width of the "reciprocal Q wave" (r = 0.64-0.71 for DE-CMR, r = 0.57-0.64 for CK-MBm, P < 0.0001). Repolarization-phase variables showed only weak correlations with MI size in the acute phase, but these correlations improved during MI healing. T-wave variables and the QRSSTT integral showed their best correlations with DE-CMR defined MI size on the precordial area, at best r = -0.57, P < 0.0001 in the chronic phase. The best performing BSPM variables could differentiate between large and small infarcts at all stages of MI.
  
  
  CONCLUSIONS
  Computed, single-lead electrocardiographic variables can estimate the final infarct size at all stages of MI, and differentiate large infarcts from small.
authors.affiliation: Division of Cardiology, Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland.|BioMag Laboratory, Hospital District of Helsinki and Uusimaa HUSLAB, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Minna M
authors.initials: MM
authors.lastname: Kylmälä
authors.affiliation: Department of Biomedical Engineering and Computational Science, Aalto University, Espoo, Finland.
authors.forename: Teijo
authors.initials: T
authors.lastname: Konttila
authors.affiliation: Division of Cardiology, Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland.|BioMag Laboratory, Hospital District of Helsinki and Uusimaa HUSLAB, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Paula
authors.initials: P
authors.lastname: Vesterinen
authors.affiliation: Department of Radiology, HUS Medical Imaging Center, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Sari M
authors.initials: SM
authors.lastname: Kivistö
authors.affiliation: Department of Radiology, HUS Medical Imaging Center, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Kirsi
authors.initials: K
authors.lastname: Lauerma
authors.affiliation: Department of Biomedical Engineering and Computational Science, Aalto University, Espoo, Finland.
authors.forename: Mats
authors.initials: M
authors.lastname: Lindholm
authors.affiliation: Department of Biomedical Engineering and Computational Science, Aalto University, Espoo, Finland.
authors.forename: Heikki
authors.initials: H
authors.lastname: Väänänen
authors.affiliation: Department of Biomedical Engineering and Computational Science, Aalto University, Espoo, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Stenroos
authors.affiliation: Division of Cardiology, Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Markku S
authors.initials: MS
authors.lastname: Nieminen
authors.affiliation: Division of Cardiology, Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Helena
authors.initials: H
authors.lastname: Hänninen
authors.affiliation: Division of Cardiology, Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Lauri
authors.initials: L
authors.lastname: Toivonen
mesh_terms: D018780:Body Surface Potential Mapping; D003287:Contrast Media; D005260:Female; D006321:Heart / Q000503:physiopathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology; D012372:ROC Curve; D015203:Reproducibility of Results; D012720:Severity of Illness Index
chemical_list: D003287:Contrast Media
keywords: body surface potential mapping; cardiac magnetic resonance imaging; electrocardiography; myocardial infarct size; myocardial infarction