title: Optimal Force-Time Integral for Pulmonary Vein Isolation According to Anatomical Wall Thickness Under the Ablation Line.
abstract: BACKGROUND
  Low contact force and force-time integral (FTI) during catheter ablation are associated with ineffective lesion formation, whereas excessively high contact force and FTI may increase the risk of complications. We sought to evaluate the optimal FTI for pulmonary vein (PV) isolation based on atrial wall thickness under the ablation line.
  
  
  RESULTS
  Contact force parameters and FTI during anatomical ipsilateral PV isolation for atrial fibrillation and atrial wall thickness were assessed retrospectively in 59 consecutive patients for their first PV isolation procedure. The PV antrum was divided into 8 segments, and the wall thickness of each segment under the ablation line was determined using multidetector computed tomography. The FTI for each ablation point was divided by the wall thickness of the PV antrum segment where each point was located to obtain FTI/wall thickness. In total, 5335 radiofrequency applications were delivered, and 85 gaps in PV isolation ablation lines and 15 dormant conductions induced by adenosine were detected. The gaps or dormant conductions were significantly associated with low contact force, radiofrequency duration, FTI, and FTI/wall thickness. Among them, FTI/wall thickness had the best prediction value for gaps or dormant conductions by receiver operating characteristic curve analysis. FTI/wall thickness of <76.4 gram-seconds per millimeter (gs/mm) predicted gaps or dormant conductions with sensitivity (88.0%) and specificity (83.6%), and FTI/wall thickness of <101.1 gs/mm was highly predictive (sensitivity 97.0%; specificity 69.6%).
  
  
  CONCLUSIONS
  FTI/wall thickness is a strong predictor of gap and dormant conduction formation in PV isolation. An FTI/wall thickness ≈100 gs/mm could be a suitable target for effective ablation.
authors.affiliation: Department of Disease Control and Homeostasis, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan Department of Cardiology, National Hospital Organization, Kanazawa Medical Center, Kanazawa, Japan akio.chikata@gmail.com.
authors.forename: Akio
authors.initials: A
authors.lastname: Chikata
authors.affiliation: Department of Disease Control and Homeostasis, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kato
authors.affiliation: Department of Cardiology, National Hospital Organization, Kanazawa Medical Center, Kanazawa, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Sakagami
authors.affiliation: Department of Cardiology, National Hospital Organization, Kanazawa Medical Center, Kanazawa, Japan.
authors.forename: Chieko
authors.initials: C
authors.lastname: Kato
authors.affiliation: Department of Cardiology, National Hospital Organization, Kanazawa Medical Center, Kanazawa, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Saeki
authors.affiliation: Department of Radiology, National Hospital Organization, Kanazawa Medical Center, Kanazawa, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kawai
authors.affiliation: Department of Disease Control and Homeostasis, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Takashima
authors.affiliation: Department of Disease Control and Homeostasis, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Murai
authors.affiliation: Department of Disease Control and Homeostasis, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Soichiro
authors.initials: S
authors.lastname: Usui
authors.affiliation: Department of Disease Control and Homeostasis, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Furusho
authors.affiliation: Department of Disease Control and Homeostasis, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Kaneko
authors.affiliation: Department of Disease Control and Homeostasis, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Takamura
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods*; D019560:Echocardiography, Three-Dimensional; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D064847:Multimodal Imaging / Q000379:methods; D011237:Predictive Value of Tests; D011667:Pulmonary Veins / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D012372:ROC Curve; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
keywords: atrial fibrillation; atrial wall thickness; contact force; force–time integral; pulmonary vein isolation