title: Phased-array intracardiac echocardiography during pulmonary vein isolation and linear ablation for atrial fibrillation.
abstract: BACKGROUND
  Fluoroscopic imaging provides limited anatomic guidance for left atrial structures. The aim of this study was to determine the utility of real-time, phased-array intracardiac echocardiography during radiofrequency ablation for atrial fibrillation.
  
  
  RESULTS
  In 29 patients undergoing pulmonary vein isolation (n = 16) or linear (n = 13) left atrial radiofrequency ablation for atrial fibrillation, intracardiac phased-array echocardiography was used to visualize left atrial anatomy and the pulmonary veins, as well as ablation and mapping catheters during ablation procedures. In the 16 pulmonary vein isolation patients, the mean pulmonary vein ostial diameters measured by venography and intracardiac echocardiography were similar for all veins positions, except that left common pulmonary vein diameters were larger as measured by echocardiography (2.50 +/- 0.29 cm) than by venography (1.79 +/- 0.50 cm, P = 0.001). The ostial diameters measured by echocardiography and venography were not correlated, however (r = 0.23, P = 0.19). As directed by echocardiography, only 1 of 25 circular mapping catheters (4%) used in 16 patients was replaced due to inappropriate sizing of the pulmonary veins. Mean pulmonary vein Doppler flow velocities increased after ablation for left-sided veins but ostial diameters were unchanged. In the linear ablation patients, the entire extent of the linear electrode array could be visualized in only 3 of 52 of catheter positions (6%) in the 13 patients. A portion of the catheter could be seen in only 50% of all target catheter positions.
  
  
  CONCLUSIONS
  Phased-array intracardiac echocardiography (1) allows sizing and positioning of pulmonary vein mapping catheters, (2) provides measures of pulmonary vein ostial diameters, (3) continuously monitors pulmonary vein Doppler flow velocities, and (4) has limited use in positioning linear ablation catheters in the left atrium.
authors.affiliation: Department of Internal Medicine, Virginia Commonwealth University's Medical College of Virginia, Richmond 23219, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Martin
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Ellenbogen
authors.forename: Yung R
authors.initials: YR
authors.lastname: Lau
authors.forename: Jeff A
authors.initials: JA
authors.lastname: Hall
authors.forename: G Neal
authors.initials: GN
authors.lastname: Kay
authors.forename: Richard K
authors.initials: RK
authors.lastname: Shepard
authors.forename: J V
authors.initials: JV
authors.lastname: Nixon
authors.forename: Mark A
authors.initials: MA
authors.lastname: Wood
mesh_terms: D000407:Alabama; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D001783:Blood Flow Velocity / Q000502:physiology; D017115:Catheter Ablation; D004452:Echocardiography; D004567:Electrodes, Implanted; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement; D008297:Male; D008875:Middle Aged; D010690:Phlebography; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D012008:Recurrence; D016896:Treatment Outcome; D014768:Virginia