title: Introduction of an expert system for the discrimination of local pulmonary vein and atrial far field signals.
abstract: BACKGROUND
  Discrimination of local and far field potentials during sinus rhythm and atrial fibrillation (AF) is essential for successful pulmonary vein (PV) isolation. We sought to introduce an expert system for the classification of electrophysiologic PV signals.
  
  
  METHODS
  For the expert system database, we analyzed ablation procedures of 50 patients with paroxysmal and persistent AF. Standard circumferential catheters and bipolar recordings were required. In a prospective trial, the expert system was compared with the performing electrophysiologists' classifications of potentials during 15 procedures. A total of 1,343 recordings of local PV and far field signals were validated by the sudden disappearance of local potentials during ablation, the presence of dissociated PV activity, and pacing maneuvers. A fast Fourier transform was applied to the individual potentials. Analysis continued in the amplitude and phase representation.
  
  
  RESULTS
  Four parameters significant (p < 0.001) for classification were identified and entered a logistic regression model. Overall sensitivity and specificity of the model was 87% with minor, nonsignificant variations for individual PVs and different underlying rhythms. Concordance with ad hoc electrophysiologists' classification of local potentials was 70%, which increased during post hoc analysis to 86% since classification of 14% of the potentials had to be revised. For these potentials, the expert system correctly predicted their local origin in 86%.
  
  
  CONCLUSIONS
  An expert system for the evaluation of electrophysiologic signals based on morphology analysis using the Fourier transform is feasible. The ease of use and online availability facilitate a widespread use for AF ablation procedures.
authors.affiliation: Heart Center Dortmund, Department of Cardiology, Dortmund, Germany, hanno.klemm@klinikumdo.de
authors.forename: Hanno Ulrich
authors.initials: HU
authors.lastname: Klemm
authors.forename: Thomas
authors.initials: T
authors.lastname: Heitzer
authors.forename: Ute
authors.initials: U
authors.lastname: Ruprecht
authors.forename: Christin
authors.initials: C
authors.lastname: Johnsen
authors.forename: Thomas
authors.initials: T
authors.lastname: Meinertz
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Ventura
mesh_terms: D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D018780:Body Surface Potential Mapping / Q000379:methods*; D005103:Expert Systems; D005260:Female; D006325:Heart Atria / Q000503:physiopathology* / Q000601:surgery; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000503:physiopathology* / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods
references.citation: J Cardiovasc Electrophysiol. 2003 Jul;14(7):698-704
references.pmid: 12930248
references.citation: Heart Rhythm. 2006 Jun;3(6):748-50
references.pmid: 16731484
references.citation: Circulation. 2000 Mar 28;101(12):1409-17
references.pmid: 10736285
references.citation: Circulation. 2002 Jun 18;105(24):2821-5
references.pmid: 12070107
references.citation: J Cardiovasc Electrophysiol. 2007 Jan;18(1):23-8
references.pmid: 17081205
references.citation: Circulation. 2004 Oct 12;110(15):2090-6
references.pmid: 15466640
references.citation: J Cardiovasc Electrophysiol. 2002 Feb;13(2):118-23
references.pmid: 11900284
references.citation: J Cardiovasc Electrophysiol. 2002 Jan;13(1):33-7
references.pmid: 11843480
references.citation: Circulation. 2004 Mar 30;109(12):1523-9
references.pmid: 15023867
references.citation: J Cardiovasc Electrophysiol. 2005 Nov;16(11):1125-37
references.pmid: 16302892
references.citation: J Cardiovasc Electrophysiol. 2004 Apr;15(4):402-6
references.pmid: 15089987
references.citation: J Cardiovasc Electrophysiol. 1999 Nov;10(11):1525-33
references.pmid: 10571372
references.citation: N Engl J Med. 1998 Sep 3;339(10):659-66
references.pmid: 9725923
references.citation: Circulation. 2005 Mar 8;111(9):1100-5
references.pmid: 15723973
references.citation: Pacing Clin Electrophysiol. 2000 Nov;23(11 Pt 2):1832-5
references.pmid: 11139936
references.citation: J Cardiovasc Electrophysiol. 2003 Dec;14(12):1311-8
references.pmid: 14678106
references.citation: J Am Coll Cardiol. 2002 Apr 17;39(8):1337-44
references.pmid: 11955852