title: Influence of high-pass filtering on noncontact mapping and ablation of atrial tachycardias.
abstract: The aim of the study was to define the impact of different high-pass filter settings (HPF) on the accuracy of mapping of ectopic atrial tachycardias (EAT) using a noncontact mapping (NCM) system. In 20 patients with 22 EAT a noncontact probe was deployed in the right (n = 19) or in the left atrium (n = 3). The device enables interpolation and analysis of unipolar electrograms. It provides information on focus localization and signal morphology. These parameters were compared in different HPF of 0.5 Hz, 2 Hz, 8 Hz, and 16 Hz. The NCM signal morphology was preserved at all HPF. An initial negative deflection recorded by NCM system showed a positive predictive value of 93% regarding the ablation success. The deviation (spatial disparity) between visualized focus origin and successful ablation site was 6.9 +/- 5.4 mm. Between two consecutive filter settings, the focus shift was more pronounced between 0.5 and 2 Hz (5.4 +/- 4.5 mm) compared to a setting between 8 and 16 Hz (2.9 +/- 2.9 mm; P < 0.05). Successful ablation was achieved in 15/18 right atrial tachycardias (83%) and in 2/3 left atrial arrhythmias. Different HPF influence NCM spatial analysis of EAT. However, a small variability in foci localization does not impact final ablation results.
authors.affiliation: Deutsches Herzzentrum and I. Med. Klinik, Technische Universität München, Munich, Germany. MAE.Schneider@t-online.de
authors.forename: Michael A E
authors.initials: MA
authors.lastname: Schneider
authors.forename: Gjin
authors.initials: G
authors.lastname: Ndrepepa
authors.forename: Stefan
authors.initials: S
authors.lastname: Weber
authors.forename: Isabel
authors.initials: I
authors.lastname: Deisenhofer
authors.forename: Albert
authors.initials: A
authors.lastname: Schömig
authors.forename: Claus
authors.initials: C
authors.lastname: Schmitt
mesh_terms: D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D013612:Tachycardia, Ectopic Atrial / Q000503:physiopathology* / Q000601:surgery*