title: Cryoballoon temperature predicts acute pulmonary vein isolation.
abstract: BACKGROUND
  Cryoballoon pulmonary vein isolation (PVI) currently requires a long cryoballoon application (CBA) time of 240 to 300 seconds, thus repeated ineffective CBA prolongs procedure duration. We hypothesized that cryoballoon temperature (CBT) may be used to discriminate between effective and ineffective CBA during freezing.
  
  
  OBJECTIVE
  This study sought to evaluate CBT as a predictor of CBA efficiency.
  
  
  METHODS
  Sixty-six patients with atrial fibrillation underwent PVI using the single big (28 mm) cryoballoon technique. CBT was continuously recorded. After each CBA (300 seconds), a Lasso catheter (Biosense Webster, Inc., Diamond Bar, California) was placed into the target pulmonary vein (PV) to determine whether electrical PV disconnection was present. Only the first CBA at each PV was analyzed to avoid cumulative effects.
  
  
  RESULTS
  The CBT was lower during CBA at superior compared with inferior PVs. When individual CBAs were grouped according to successful/failed PVI, CBT was lower for those CBAs that resulted in successful PVI at all time points analyzed. To test the performance of CBT to predict failed CBA, receiver-operator curves were constructed. A minimal CBT of ≥ -42°C/ -39°C (superior/inferior PVs) predicted failed PVI with 73%/92% specificity (area under the curve 0.82/0.81); positive predictive value (PPV) 74%/74%. A minimal CBT of < -51°C was invariably associated with PVI. After 120 seconds of freezing, a CBT of ≥ -36°C/ -33°C (superior/inferior PVs) predicted failed PVI with 97%/95% specificity (area under the curve 0.82/0.76); PPV 82%/80%.
  
  
  CONCLUSIONS
  Balloon temperature predicts successful target PVI during cryoablation and may serve in the early identification of noneffective balloon applications.
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany. a.fuernkranz@gmail.com
authors.forename: Alexander
authors.initials: A
authors.lastname: Fürnkranz
authors.forename: Ilka
authors.initials: I
authors.lastname: Köster
authors.forename: K R Julian
authors.initials: KR
authors.lastname: Chun
authors.forename: Andreas
authors.initials: A
authors.lastname: Metzner
authors.forename: Shibu
authors.initials: S
authors.lastname: Mathew
authors.forename: Melanie
authors.initials: M
authors.lastname: Konstantinidou
authors.forename: Feifan
authors.initials: F
authors.lastname: Ouyang
authors.forename: Karl Heinz
authors.initials: KH
authors.lastname: Kuck
mesh_terms: D001281:Atrial Fibrillation / Q000601:surgery*; D003452:Cryosurgery / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000601:surgery*; D012189:Retrospective Studies; D013696:Temperature; D016896:Treatment Outcome