title: Integrated electroanatomic mapping with three-dimensional computed tomographic images for real-time guided ablations.
abstract: BACKGROUND
  New ablation strategies for atrial fibrillation or nonidiopathic ventricular tachycardia are increasingly based on anatomic consideration and require the placement of ablation lesions at the correct anatomic locations. This study sought to evaluate the accuracy of the first clinically available image integration system for catheter ablation on 3-dimensional (3D) computed tomography (CT) images in real time.
  
  
  RESULTS
  After midline sternotomy, 2.3-mm CT fiducial markers were attached to the epicardial surface of each cardiac chamber in 9 mongrel dogs. Detailed 3D cardiac anatomy was reconstructed from contrast-enhanced, high-resolution CT images and registered to the electroanatomic maps of each cardiac chamber. To assess accuracy, targeted ablations were performed at each of the fiducial markers guided only by the reconstructed 3D images. At autopsy, the position error was 1.9+/-0.9 mm for the right atrium, 2.7+/-1.2 mm for the right ventricle, 1.8+/-1.0 mm for the left atrium, and 2.3+/-1.1 mm for the left ventricle. To evaluate the system's guidance of more complex clinical ablation strategies, ablations of the cavotricuspid isthmus (n=4), fossa ovalis (n=4), and pulmonary veins (n=6) were performed, which resulted in position errors of 1.8+/-1.5, 2.2+/-1.3, and 2.1+/-1.2 mm, respectively. Retrospective analysis revealed that a combination of landmark registration and the target chamber surface registration resulted in <3 mm accuracy in all 4 cardiac chambers.
  
  
  CONCLUSIONS
  Image integration with high-resolution 3D CT allows accurate placement of anatomically guided ablation lesions and can facilitate complex ablation strategies. This may provide significant advantages for anatomically based procedures such as ablation of atrial fibrillation and nonidiopathic ventricular tachycardia.
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Dong
authors.forename: Hugh
authors.initials: H
authors.lastname: Calkins
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Solomon
authors.forename: Shenghan
authors.initials: S
authors.lastname: Lai
authors.forename: Darshan
authors.initials: D
authors.lastname: Dalal
authors.forename: Albert C
authors.initials: AC
authors.lastname: Lardo
authors.forename: Al
authors.initials: A
authors.lastname: Lardo
authors.forename: Erez
authors.initials: E
authors.lastname: Brem
authors.forename: Assaf
authors.initials: A
authors.lastname: Preiss
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Berger
authors.forename: Henry
authors.initials: H
authors.lastname: Halperin
authors.forename: Timm
authors.initials: T
authors.lastname: Dickfeld
mesh_terms: D000818:Animals; D001344:Autopsy; D017115:Catheter Ablation / Q000379:methods*; D004285:Dogs; D022062:Electrophysiologic Techniques, Cardiac; D021621:Imaging, Three-Dimensional; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*