title: Steerable versus non-steerable sheaths during pulmonary vein isolation: impact of left atrial enlargement on the catheter-tissue contact force.
abstract: OBJECTIVE
  The influence of left atrial (LA) enlargement on the efficacy of steerable sheath usage during pulmonary vein (PV) isolation is poorly understood. Here, we compared the catheter-tissue contact force (CF) and clinical outcomes between steerable and non-steerable sheaths among patients with different severities of LA enlargement.
  
  
  METHODS
  In this prospective observational study, 90 consecutive atrial fibrillation patients scheduled for PV isolation (paroxysmal, 67 %) were enrolled and divided into tertiles of the LA volume (LA1, <124 cm3; LA2, 124 to 145 cm3; LA3, ≥146 cm3). An ipsilateral PV isolation was completed using either a steerable (n = 57) or non-steerable sheath (n = 33).
  
  
  RESULTS
  The average CF of each ipsilateral PV was lower in the LA3 group (right 13.8 ± 5.8 g; left 9.7 ± 5.2 g) than LA1 (right 15.6 ± 6.8 g, p = 0.005; left 12.5 ± 5.6 g, p < 0.0001) or LA2 (right 15.2 ± 7.3 g, p = 0.04; left 12.6 ± 5.3 g, p < 0.0001) groups. In total, the average CF around the left PVs was significantly higher with steerable sheaths than without (12.7 ± 5.5 vs. 10.2 ± 4.9 g, p = 0.03). Subgroup analysis revealed that a tendency toward higher CF around the left PVs was observed in the LA3 group (12.3 ± 7.3 vs. 8.5 ± 3.9 g, p = 0.08) but was not in the LA1 and LA2 groups. Further, in the LA3 group, steerable sheath usage showed better clinical outcomes: shorter procedural (55 ± 29 min vs. 81 ± 39 min, p = 0.04) and fluoroscopic times (27 ± 11 min vs. 37 ± 17 min, p = 0.045) and a tendency toward a lower 1-year AF recurrence rate (39 vs. 12 %, p = 0.09).
  
  
  CONCLUSIONS
  The beneficial effects of using steerable sheaths were more prominent in patients with severe LA enlargement.
authors.affiliation: Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki-shi, Hyogo, 660-8511, Japan. masuda-masaharu@kanrou.net.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Masuda
authors.affiliation: Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki-shi, Hyogo, 660-8511, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Fujita
authors.affiliation: Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki-shi, Hyogo, 660-8511, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Iida
authors.affiliation: Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki-shi, Hyogo, 660-8511, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Okamoto
authors.affiliation: Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki-shi, Hyogo, 660-8511, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ishihara
authors.affiliation: Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki-shi, Hyogo, 660-8511, Japan.
authors.forename: Kiyonori
authors.initials: K
authors.lastname: Nanto
authors.affiliation: Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki-shi, Hyogo, 660-8511, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kanda
authors.affiliation: Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki-shi, Hyogo, 660-8511, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Shiraki
authors.affiliation: Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki-shi, Hyogo, 660-8511, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Sunaga
authors.affiliation: Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki-shi, Hyogo, 660-8511, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Matsuda
authors.affiliation: Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki-shi, Hyogo, 660-8511, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Uematsu
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006325:Heart Atria / Q000473:pathology*; D006329:Heart Conduction System / Q000601:surgery; D006801:Humans; D006984:Hypertrophy / Q000473:pathology; D008297:Male; D016343:Monitoring, Intraoperative / Q000295:instrumentation* / Q000379:methods; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000601:surgery*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D016896:Treatment Outcome
keywords: Atrial fibrillation; Contact force; Left atrial size; Pulmonary vein isolation; Steerable sheath