title: A unipolar coronary sinus mapping study of patients with left-sided atrioventricular accessory pathways.
abstract: So-called unipolar 'PQS pattern' is widely accepted as a hallmark of successful catheter ablation of the left-sided atrioventricular accessory pathway. However, the unipolar nature of the electrogram and the site-dependent appearance of this characteristic pattern are poorly understood. Therefore, unipolar coronary sinus (CS) mapping was performed using a multipolar fine electrode in patients with Wolff-Parkinson-White (WPW) syndrome associated with an antegrade left-sided accessory pathway (case group) and those with a concealed left-sided accessory pathway or atrioventricular nodal reentrant tachycardia (control group) under sinus rhythm and fixed high right atrial, CS ostial, and distal pacing. In both groups, the unipolar CS atrial electrogram showed intrinsic negative deflection (initial positive followed by negative parts) with considerable variation depending on the recording site. This unipolar configuration of the atrial electrogram was not influenced by different activation sequences during pacing at various sites. The case group exhibited a unipolar 'PQS pattern' at successful ablation sites for the left lateral to anterolateral accessory pathway. However, this was not true for the left posteroseptal accessory pathway, possibly because the negative part of the atrial electrogram distorted the 'PQS pattern' as an intervening dip. In conclusion, the site-dependent variations of the unipolar CS atrial electrogram underlie the limited usefulness of the 'PQS pattern' in left posteroseptal accessory pathway localization.
authors.affiliation: Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Kubota
authors.forename: Kazuta
authors.initials: K
authors.lastname: Nakasuga
authors.forename: Toru
authors.initials: T
authors.lastname: Maruyama
authors.forename: Norihiro
authors.initials: N
authors.lastname: Ueda
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ito
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Kaji
authors.forename: Mine
authors.initials: M
authors.lastname: Harada
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001283:Atrioventricular Node / Q000601:surgery*; D002304:Cardiac Pacing, Artificial; D017115:Catheter Ablation; D004562:Electrocardiography; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology; D014927:Wolff-Parkinson-White Syndrome / Q000503:physiopathology* / Q000601:surgery