title: Non-invasive magnetocardiographic localization of ventricular pre-excitation in the Wolff-Parkinson-White syndrome using a realistic torso model.
abstract: This study was performed to evaluate the accuracy of magnetocardiography in non-invasive localization of the ventricular pre-excitation site in patients suffering from the Wolff-Parkinson-White (WPW) syndrome. Twelve WPW patients were studied, in whom the pre-excitation caused serious supraventricular arrhythmias refractory to drug therapy. Magnetocardiographic measurements were performed in a magnetically shielded room, and non-invasive localization was computed from preprocessed magnetic signals using a current dipole source in a realistically shaped digital torso. All patients underwent intra-operative multicatheter mapping and subsequent dissection of the accessory atrioventricular connection. The intra-operative localization results were marked on magnetic resonance images of the heart, where magnetocardiographic results were also superimposed to allow comparison. The average of the three-dimensional differences between the magnetocardiographic and the invasive results was 2.1 +/- 0.9 cm. In all cases, the computed localization result was in the same or adjacent anatomical region as the intra-operative result. The present results show that the magnetocardiographic method using a realistic torso model is capable of localizing pre-excitation sites with sufficient accuracy to provide extra information so that non-pharmacological therapeutic interventions can be applied.
authors.affiliation: Helsinki University of Technology, Department of Technical Physics, Espoo, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Nenonen
authors.forename: M
authors.initials: M
authors.lastname: Mäkijärvi
authors.forename: L
authors.initials: L
authors.lastname: Toivonen
authors.forename: K
authors.initials: K
authors.lastname: Forsman
authors.forename: M
authors.initials: M
authors.lastname: Leiniö
authors.forename: J
authors.initials: J
authors.lastname: Montonen
authors.forename: A
authors.initials: A
authors.lastname: Järvinen
authors.forename: P
authors.initials: P
authors.lastname: Keto
authors.forename: P
authors.initials: P
authors.lastname: Hekali
authors.forename: T
authors.initials: T
authors.lastname: Katila
mesh_terms: D000328:Adult; D005260:Female; D006329:Heart Conduction System / Q000473:pathology* / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008280:Magnetics; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D014927:Wolff-Parkinson-White Syndrome / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology