title: The incidence of phrenic nerve injury during pulmonary vein isolation using the second-generation 28 mm cryoballoon.
abstract: BACKGROUND
  The second-generation cryoballoon (CB; Arctic Front Advance, Medtronic Inc., Minneapolis, MN, USA) has demonstrated greater procedural efficacy compared to the original CB. Whether increased efficacy translates into a higher incidence of phrenic nerve (PN) injury needs further evaluation.
  
  
  METHODS
  In patients with drug-refractory paroxysmal atrial fibrillation (AF) or short-standing persistent AF, pulmonary vein isolation (PVI) was performed using the 28 mm second-generation CB. During cryoenergy delivery along the septal PVs, continuous PN pacing was performed. The freeze cycle was aborted in case of weakening or loss of diaphragmatic contraction.
  
  
  RESULTS
  A total of 115 patients (42 female, mean age 61 ± 11 years, mean LA-diameter 43 ± 6 mm) with a history of paroxysmal AF (93/115 patients [81%]) or short-standing persistent AF (22/115 patients [19%]) underwent CB-based PVI. A total 445 of 448 (99%) PVs were isolated successfully. PN palsy (PNP) occurred in 4 of 115 (3.5%) patients, while applying cryoenergy to the right superior PV. Despite prompt interruption of the freezing cycle, PN function failed to recover during the periprocedural phase. PN recovery was observed as late as 10 months postablation.
  
  
  CONCLUSIONS
  Using the second-generation 28 mm CB, PNP occurred in 4 of 115 (3.5%) patients. While 1 of 4 PNP recovered 10 months after ablation, long-term outcome in the remaining 3 patients is currently unknown due to the rather short follow-up period.
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Metzner
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Rausch
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Lemes
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Bruno
authors.initials: B
authors.lastname: Reissmann
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Bardyszewski
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Tilz
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Rillig
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Shibu
authors.initials: S
authors.lastname: Mathew
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Deiss
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kamioka
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Toennis
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Tina
authors.initials: T
authors.lastname: Lin
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Feifan
authors.initials: F
authors.lastname: Ouyang
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Kuck
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Erik
authors.initials: E
authors.lastname: Wissner
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery*; D062906:Cardiac Catheters; D003452:Cryosurgery / Q000009:adverse effects* / Q000295:instrumentation*; D003964:Diaphragm / Q000294:innervation*; D004867:Equipment Design; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D059348:Peripheral Nerve Injuries / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D010791:Phrenic Nerve / Q000293:injuries*; D011667:Pulmonary Veins / Q000503:physiopathology / Q000601:surgery*; D020127:Recovery of Function; D013997:Time Factors; D016896:Treatment Outcome
keywords: atrial fibrillation; catheter ablation; cryoablation; cryoballoon ablation; phrenic nerve mapping; pulmonary vein isolation