title: Impact of catheter tip-tissue contact on three-dimensional left atrial geometries: Relationship between the external structures and anatomic distortion of 3D fast anatomical mapping and high contact force guided images.
abstract: BACKGROUND
  A high catheter tip-tissue contact force (CF) with the myocardium may cause 3-dimensional (3D) map distortion, however, the influence of external structures surrounding the left atrium (LA) on that distortion remains unknown. This study characterized the impact of high CF mapping on the local LA geometry distortion.
  
  
  METHODS
  Thirty AF patients underwent 3D-ultrasound merged with CT images (3D-Merge-CT). The LA area in contact with external structures was identified by enhanced CT. Fast-electroanatomical-mapping (FAM) geometries were created by two methods, point-by-point mapping with high (>10g) CFs (high-CF guided-FAM), followed by that with multielectrode-mapping catheters (conventional-FAM). The resulting geometries were compared with the 3D-Merge-CT images.
  
  
  RESULTS
  Three representative anatomical contact areas (ascending aorta-vs.-anterior wall, descending aorta-vs.-left pulmonary vein [PV], and vertebrae-vs.-posterior wall) were identified. The PV antrum distorted distance on the 3D-Merge-CT was significantly longer for high-CF guided-FAMs than conventional-FAMs (1.7[0-3.6] vs. 0[0-1.8]mm, P<0.0001). In high-CF maps, the distorted distance significantly differed between regions with and without contact areas in both the PV antrum (0[0-0.17] vs. 1.7[0-3.9]mm, P=0.0201) and LA body region (0[0-1.5] vs. 1.7[0.7-2.2]mm, P<0.005). The catheter tip-tissue CF did not correlate with the distorted distance (r=0.08, P=0.46), and a multivariate analysis revealed that the absence of anatomical contact areas was strongly associated with significant local distortion, independent of the CF.
  
  
  CONCLUSIONS
  High-CF guided mapping yields greater 3D-image anatomical distortion than conventional-FAM methods. That distortion was attenuated by regions with anatomical contact areas, suggesting that regional anatomic distortion is involved in the existence of external structures surrounding the LA.
authors: Department of Cardiology, Dokkyo Medical University Koshigaya Hospital, Saitama, Japan.
authors: Naofumi
authors: N
authors: Anjo
authors: Department of Cardiology, Dokkyo Medical University Koshigaya Hospital, Saitama, Japan. Electronic address: nshiro@dokkyomed.ac.jp.
authors: Shiro
authors: S
authors: Nakahara
authors: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors: Yasuo
authors: Y
authors: Okumura
authors: Department of Cardiology, Dokkyo Medical University Koshigaya Hospital, Saitama, Japan.
authors: Yuichi
authors: Y
authors: Hori
authors: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors: Koichi
authors: K
authors: Nagashima
authors: Department of Cardiology, Dokkyo Medical University Koshigaya Hospital, Saitama, Japan.
authors: Takaaki
authors: T
authors: Komatsu
authors: Department of Cardiology, Dokkyo Medical University Koshigaya Hospital, Saitama, Japan.
authors: Akiko
authors: A
authors: Hayashi
authors: Department of Cardiology, Dokkyo Medical University Koshigaya Hospital, Saitama, Japan.
authors: Sayuki
authors: S
authors: Kobayashi
authors: Department of Cardiology, Dokkyo Medical University Koshigaya Hospital, Saitama, Japan.
authors: Yoshihiko
authors: Y
authors: Sakai
authors: Department of Cardiology, Dokkyo Medical University Koshigaya Hospital, Saitama, Japan.
authors: Isao
authors: I
authors: Taguchi
mesh_terms: D000368:Aged; D020517:Atrial Appendage / Q000000981:diagnostic imaging* / Q000473:pathology; D001281:Atrial Fibrillation / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D062906:Cardiac Catheters; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods; D022062:Electrophysiologic Techniques, Cardiac; D004867:Equipment Design; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007564:Japan; D008297:Male; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care; D011667:Pulmonary Veins / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Atrial fibrillation; Catheter ablation; Contact force