title: Impact of the order of the targeted pulmonary vein on the vagal response during second-generation cryoballoon ablation.
abstract: Radiofrequency applications around pulmonary vein (PV) ostia often induce vagal reflexes.
  
  
  
  This study aimed to evaluate the impact of the order of the targeted PV on the vagal response during second-generation cryoballoon ablation.
  
  
  
  Eighty-one consecutive paroxysmal atrial fibrillation (AF) patients undergoing cryoballoon ablation were prospectively enrolled. PV isolation was performed with one 28-mm second-generation balloon using a 3-minute freeze technique. In the first 39 patients, the left superior PV (LSPV) was initially targeted. In the second 42, the LSPV was targeted following the right PVs.
  
  
  
  Baseline rhythms were sinus rhythm and AF in 34 and 5 patients in the first group, and 34 and 8 in the second group, respectively. In the first group, sinus bradycardia/arrest requiring back-up pacing occurred in 13 patients (38.2%) at a median of 41.0 (10.0-55.5) seconds after balloon deflation (90 [60-100] seconds post freezing), and pauses requiring pacing in 1 (20.0%) with AF. In the second group, no sinus bradycardia/arrest occurred throughout the procedure; however, atrioventricular block requiring back-up pacing occurred 21 seconds after balloon deflation in 1 patient in whom right superior PV (RSPV) ablation was performed for only 60 seconds owing to right phrenic nerve injury. The cycle length was similar at baseline and post PV isolation between the 2 groups, and significantly shorter during RSPV ablation (P < .0001) in both. In total, marked vagal responses were significantly higher in the first than second group (14/39 vs 1/42, P < .0001).
  
  
  
  LSPV cryoballoon ablation often provoked marked vagal responses; however, preceding RSPV ablation markedly suppressed this response.
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Japan,. Electronic address: mshinsuke@k3.dion.ne.jp.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Miyazaki
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakamura
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Taniguchi
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hachiya
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Ichihara
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Japan.
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Takagi
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Japan.
authors.forename: Jin
authors.initials: J
authors.lastname: Iwasawa
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Kuroi
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirao
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Japan.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Iesaka
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D054537:Atrioventricular Block / Q000209:etiology / Q000517:prevention & control; D001919:Bradycardia / Q000209:etiology / Q000517:prevention & control; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods; D003452:Cryosurgery / Q000009:adverse effects / Q000379:methods; D005260:Female; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D007431:Intraoperative Complications / Q000175:diagnosis / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States; D014630:Vagus Nerve / Q000503:physiopathology
keywords: Atrial fibrillation; Autonomic nervous system; Catheter ablation; Cryoballoon; Pulmonary vein isolation