title: Quantification of cardiac magnetic field orientation during ventricular de- and repolarization.
abstract: We compared the stability and discriminatory power of different methods of determining cardiac magnetic field map (MFM) orientation within the context of coronary artery disease (CAD). In 27 healthy subjects and 24 CAD patients, multichannel magnetocardiograms were registered at rest. MFM orientation was determined during QT interval using: (a) locations of the positive and negative centres-of-gravity, (b) locations of the field extrema and (c) the direction of the maximum field gradient. Deviation from normal orientation quantified the ability of each approach to discriminate between healthy and CAD subjects. Although the course of orientation was similar for all methods, receiver operating characteristic analysis showed the best discrimination of CAD patients for the centre-of-gravity approach (area-under-the-curve = 86%), followed by the gradient (84%) and extrema (76%) methods. Consideration of methodological and discriminatory advantages with respect to noninvasive diagnosis of CAD suggests that the centres-of-gravity method is the most suited one.
authors.affiliation: Department of Biomagnetism, Grönemeyer Institute of Microtherapy, Bochum, Germany. petervl@microtherapy.de
authors.forename: Peter
authors.initials: P
authors.lastname: Van Leeuwen
authors.forename: Birgit
authors.initials: B
authors.lastname: Hailer
authors.forename: Silke
authors.initials: S
authors.lastname: Lange
authors.forename: Anita
authors.initials: A
authors.lastname: Klein
authors.forename: Daniel
authors.initials: D
authors.lastname: Geue
authors.forename: Katrin
authors.initials: K
authors.lastname: Seybold
authors.forename: Christian
authors.initials: C
authors.lastname: Poplutz
authors.forename: Dietrich
authors.initials: D
authors.lastname: Grönemeyer
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000473:pathology; D004574:Electromagnetic Fields; D005260:Female; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D015225:Magnetoencephalography / Q000295:instrumentation / Q000379:methods; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity