title: Novel Technique to Prevent Phrenic Nerve Injury During Pulmonary Vein Isolation Using Preprocedural Imaging.
abstract: BACKGROUND
  Phrenic nerve (PN) injury is one of the major complications of pulmonary vein isolation (PVI). Pace mapping for PN capture is routinely used to identify areas with high risk for injury along the anterior border of the right pulmonary veins (PVs). Our aim was to evaluate the feasibility of using preprocedural imaging to identify areas where no PN capture is possible along the anterior border of the right PVs, thus avoiding the need for pace mapping during PVI.
  
  
  RESULTS
  It was hypothesized that PN capture along the anterior border of the right PVs does not occur in the area where the right and left atria overlap. Three-dimensional segmentation of both atria was performed on preprocedural magnetic resonance and computed tomography angiograms in 40 patients before undergoing PVI. The area of overlap between the right and left atria was delineated. Image registration was performed during the procedure. Using pacing, regions with and without PN capture were marked along the anterior border of the right PVs. A total of 361 points were tested for PN stimulation (9 ± 4 points/patient). PN capture occurred in 97 out of the 189 points (51%) in the area with no overlap between the right and left atria. No PN capture occurred in the area of overlap (172 points, P< 0.001).
  
  
  CONCLUSIONS
  Delineation of the area of overlap between the right and left atria derived from preprocedural imaging reliably identifies regions where PN pace capture does not occur. Testing for PN stimulation before ablation may not be necessary in these regions.
authors.affiliation: Heart Center, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: Attila
authors.initials: A
authors.lastname: Roka
authors.affiliation: Heart Center, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: E Kevin
authors.initials: EK
authors.lastname: Heist
authors.affiliation: Heart Center, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: Marwan
authors.initials: M
authors.lastname: Refaat
authors.affiliation: Heart Center, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Ruskin
authors.affiliation: Heart Center, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: Moussa
authors.initials: M
authors.lastname: Mansour
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006329:Heart Conduction System / Q000601:surgery; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D061214:Patient Safety; D059348:Peripheral Nerve Injuries / Q000209:etiology / Q000517:prevention & control*; D010791:Phrenic Nerve / Q000293:injuries*; D011300:Preoperative Care / Q000379:methods; D011667:Pulmonary Veins / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome
keywords: atrial fibrillation; electroanatomical mapping; phrenic nerve; pulmonary vein isolation; radiofrequency ablation