title: Identification of atrial tissue in pulmonary veins using intravascular ultrasound.
abstract: BACKGROUND
  Atrial fibrillation (AF) is initiated by ectopic beats originating in the sleeve of atrial tissue in pulmonary veins (PVs). Circumferential ablation of PVs can, thus, result in a cure of AF. Identification of this PV arrhythmogenic tissue has been exclusively on the basis of electrophysiologic recordings. The purpose of this study was to visualize this tissue using intravascular ultrasound (IVUS). Methods and results In all, 15 patients undergoing AF ablation had IVUS studies of their PVs. A total of 21 veins had a wall thickness less than 0.1 mm, whereas 31 veins had well-demarcated areas of thickening measuring 0.81 +/- 0.32 mm. Electrophysiologic recordings from these thickened areas showed typical high-frequency potentials associated with arrhythmogenic atrial tissue in the PVs. Ectopic beats initiating AF always originated from these areas. PVs without thickening on IVUS did not have these potentials.
  
  
  CONCLUSIONS
  IVUS permits visualization of atrial tissue in the PVs, and arrhythmogenic PVs are qualitatively and quantitatively different from nonarrhythmogenic PVs.
authors.affiliation: Department of Medicine, Montreal Heart Institute.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Guerra
authors.forename: Bernard
authors.initials: B
authors.lastname: Thibault
authors.forename: Marc
authors.initials: M
authors.lastname: Dubuc
authors.forename: Mario
authors.initials: M
authors.lastname: Talajic
authors.forename: Denis
authors.initials: D
authors.lastname: Roy
authors.forename: Jacques
authors.initials: J
authors.lastname: Crépeau
authors.forename: Stanley
authors.initials: S
authors.lastname: Nattel
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Tardif
mesh_terms: D000200:Action Potentials; D000328:Adult; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000601:surgery; D018880:Atrial Premature Complexes / Q000175:diagnosis / Q000601:surgery; D017115:Catheter Ablation; D003251:Constriction, Pathologic / Q000175:diagnosis / Q000601:surgery; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D013612:Tachycardia, Ectopic Atrial / Q000175:diagnosis / Q000601:surgery; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional