title: Development of an electrophysiology (EP)-enabled intracardiac ultrasound catheter integrated with NavX 3-dimensional electrofield mapping for guiding cardiac EP interventions: experimental studies.
abstract: OBJECTIVE
  We have developed an integrated high-resolution intracardiac echocardiography (ICE) catheter for electrophysiology (EP) testing, which can be coregistered in 3-dimensional space with EP testing and ablation catheters using electrofield sensing.
  
  
  METHODS
  Twelve open-chest pigs (34-55 kg) and 3 closed-chest pigs were studied. After introduction from the jugular or femoral venous locations, the 9F side-looking, highly steerable (0 degrees -180 degrees), 64-element array catheters could be manipulated easily throughout the right side of the heart. Multisite cardiac pacing was performed for assessing left ventricular (LV) synchrony using tissue Doppler methods. Also, in the open-chest pigs, right atrial (RA) and right ventricular (RV) ablations were performed with a separate radio frequency catheter under fluoroscopic guidance and visualized with ICE to characterize the changes. In the 3 closed-chest pigs, electrofield NavX 3-dimensional coregistration (St Jude Medical Corp, Minneapolis, MN) allowed us to test whether this additional feature could shorten the time necessary to perform 4 targeted ablations in each animal while imaging the ablation catheter and the adjacent region by ICE.
  
  
  RESULTS
  Intracardiac anatomy, tricuspid, aortic, pulmonary, and mitral valve function, and pulmonary vein flow were all imaged reproducibly from scanning locations in the RA or RV in all animals, along with assessment of cardiac motion and the effects of multisite pacing. Three-dimensional electrofield displays detailed the spatial relationship between the ICE catheter and ablation catheters such that the time to visualize and ablate 4 sites in each of the 3 closed-chest animals was reduced.
  
  
  CONCLUSIONS
  This new technology is a first step in the integration of ICE with EP procedures.
authors.affiliation: Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, L608, Portland, OR 97239-3098, USA.
authors.forename: Xiao Kui
authors.initials: XK
authors.lastname: Li
authors.forename: James
authors.initials: J
authors.lastname: Pemberton
authors.forename: Kai
authors.initials: K
authors.lastname: Thomenius
authors.forename: Aaron
authors.initials: A
authors.lastname: Dentinger
authors.forename: Robert I
authors.initials: RI
authors.lastname: Lowe
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ashraf
authors.forename: K Kirk
authors.initials: KK
authors.lastname: Shung
authors.forename: Raymond
authors.initials: R
authors.lastname: Chia
authors.forename: Douglas N
authors.initials: DN
authors.lastname: Stephens
authors.forename: Matthew
authors.initials: M
authors.lastname: O'Donnell
authors.forename: Aman
authors.initials: A
authors.lastname: Mahajan
authors.forename: Seshadri
authors.initials: S
authors.lastname: Balaji
authors.forename: Kalyanam
authors.initials: K
authors.lastname: Shivkumar
authors.forename: David J
authors.initials: DJ
authors.lastname: Sahn
mesh_terms: D000818:Animals; D018780:Body Surface Potential Mapping / Q000295:instrumentation* / Q000379:methods; D006328:Cardiac Catheterization / Q000295:instrumentation* / Q000379:methods; D019560:Echocardiography, Three-Dimensional / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D013552:Swine; D014159:Transducers; D018084:Ultrasonography, Interventional / Q000295:instrumentation* / Q000379:methods