title: Cryoballoon ablation during atrial fibrillation is associated with faster temperature drop and lower freezing temperatures.
abstract: OBJECTIVE
  Our aim was to analyse the temperature behaviour during second-generation cryoballoon ablation (CB-A) in patients with ongoing atrial fibrillation (AF) compared with those in sinus rhythm (SR).
  
  
  METHODS
  Consecutive patients with drug-resistant AF who underwent pulmonary vein (PV) isolation by CB-A from April 2014 to May 2015 were analysed. The exclusion criteria were any contraindication for the procedure including the presence of an intracavitary thrombus, uncontrolled heart failure, contraindications to general anaesthesia and cardioversion to SR during the ablation procedure.
  
  
  RESULTS
  A total amount of 323 consecutive patients having undergone PV isolation by means of CB-A (male 66 %, age 56.1 ± 13.4 years) was enrolled. During ablation in the left-sided PVs, time needed to reach -20°, -30° and -40° was significantly shorter in patients with AF than those in SR. During ablation in the right superior pulmonary vein (RSPV), time to reach -30° and -40° was also significantly longer in patients with AF; during ablation in the right inferior pulmonary vein (RIPV), although the temperature drop was faster in the AF group, times needed to reach -20°, -30° and -40° were not significantly prolonged compared with those in the SR group. Temperatures attained at 60 s, and minimal temperatures were also significantly lower in the AF group during all PV ablations except RIPV.
  
  
  CONCLUSIONS
  The temperature drop during AF cryoablation was significantly faster and attained significantly lower freezing degrees in patients with ongoing AF during the procedure compared with those in SR. This finding resulted markedly significant during each PV isolation except for RIPV cryoablation.
authors.affiliation: Heart Rhythm Management Center, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium. mugnai.giacomo@gmail.com.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Mugnai
authors.affiliation: Heart Rhythm Management Center, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium.
authors.forename: Darragh
authors.initials: D
authors.lastname: Moran
authors.affiliation: Heart Rhythm Management Center, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium.
authors.forename: Erwin
authors.initials: E
authors.lastname: Ströker
authors.affiliation: Heart Rhythm Management Center, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium.
authors.forename: Diego
authors.initials: D
authors.lastname: Ruggiero
authors.affiliation: Heart Rhythm Management Center, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium.
authors.forename: Hugo Enrique
authors.initials: HE
authors.lastname: Coutino-Moreno
authors.affiliation: Heart Rhythm Management Center, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium.
authors.forename: Ken
authors.initials: K
authors.lastname: Takarada
authors.affiliation: Heart Rhythm Management Center, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium.
authors.forename: Valentina
authors.initials: V
authors.lastname: De Regibus
authors.affiliation: Heart Rhythm Management Center, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium.
authors.forename: Rajin
authors.initials: R
authors.lastname: Choudhury
authors.affiliation: Electrophysiology Unit, Maria Cecilia Hospital, Cotignola, Italy.
authors.forename: Saverio
authors.initials: S
authors.lastname: Iacopino
authors.affiliation: Electrophysiology Unit, Maria Cecilia Hospital, Cotignola, Italy.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Filannino
authors.affiliation: Department of Anaesthesiology, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium.
authors.forename: Vincent
authors.initials: V
authors.lastname: Umbrain
authors.affiliation: Department of Anaesthesiology, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium.
authors.forename: Stefan
authors.initials: S
authors.lastname: Beckers
authors.affiliation: Heart Rhythm Management Center, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium.
authors.forename: Pedro
authors.initials: P
authors.lastname: Brugada
authors.affiliation: Heart Rhythm Management Center, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium.
authors.forename: Carlo
authors.initials: C
authors.lastname: de Asmundis
authors.affiliation: Heart Rhythm Management Center, UZ Brussel-VUB, Laarbeeklaan 101, 1090, Brussels, Belgium.
authors.forename: Gian-Battista
authors.initials: GB
authors.lastname: Chierchia
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery*; D001831:Body Temperature; D001833:Body Temperature Regulation; D017115:Catheter Ablation / Q000379:methods*; D003452:Cryosurgery / Q000379:methods*; D005615:Freezing; D006801:Humans; D008875:Middle Aged; D011667:Pulmonary Veins / Q000503:physiopathology* / Q000601:surgery; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013696:Temperature; D016896:Treatment Outcome
keywords: Ablation; Atrial fibrillation; Cryoballoon; Pulmonary vein isolation; Temperature