title: Active Atrial Function and Atrial Scar Burden After Multiple Catheter Ablations of Persistent Atrial Fibrillation.
abstract: BACKGROUND
  Extensive and repeated substrate modification (SM) is frequently performed as an ablation strategy in persistent atrial fibrillation (persAF). The effect of these extended ablation strategies on atrial function has not been investigated sufficiently so far. The purpose was to assess atrial function by cardiac magnetic resonance (CMR) and its association with left atrial (LA) scar burden by electroanatomical voltage-mapping after multiple persAF ablation procedures.
  
  
  METHODS
  We included 16 persAF patients who had ≥2 SM procedures and a control group (CG) of 21 persAF patients without prior ablation. CMR was performed in sinus rhythm at least 4 weeks after the last cardioversion. Active left and right (RA) atrial emptying fractions (AEF) as well as peak active left atrial appendage (LAA) emptying velocities were obtained by CMR flow measurements. Furthermore, LA scar burden was quantified on electroanatomical voltage maps by the portion of points with local voltage amplitude <0.2 mV.
  
  
  RESULTS
  We found median LA-AEF to be lower (13 [9-22] vs 32 [26-36] %, P < 0.001) and median LA scar burden to be higher (40 [20-68] vs nine [3-18] %, P < 0.05) in the SM group compared with the CG. Furthermore, a significant correlation was found between mean LA voltage and LA-AEF (r2= 0.62, P < 0.001). No significant differences were detected with respect to median RA-AEF (41 [28-48] vs 47 [35-50] %, P = 0.43) and median peak LAA emptying velocities (30 [16-40] vs 17 [13-28] cm/s, P = 0.07).
  
  
  CONCLUSIONS
  Active LA function is preserved but significantly impaired and associated with ablation-related LA scar burden after multiple extensive persAF ablations.
authors.affiliation: University Heart Center, Department of Cardiology - Electrophysiology, Hamburg, Germany.
authors.forename: Jana M
authors.initials: JM
authors.lastname: Nührich
authors.affiliation: University Heart Center, Department of Cardiology - Electrophysiology, Hamburg, Germany.
authors.forename: Anne C
authors.initials: AC
authors.lastname: Geisler
authors.affiliation: University Hospital Cologne, Heart Center, Department of Electrophysiology, Cologne, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Steven
authors.affiliation: University Heart Center, Department of Cardiology - Electrophysiology, Hamburg, Germany.
authors.forename: Boris A
authors.initials: BA
authors.lastname: Hoffmann
authors.affiliation: University Heart Center, Department of Cardiology - Electrophysiology, Hamburg, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Schäffer
authors.affiliation: University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg, Germany.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Lund
authors.affiliation: Philips Research Hamburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Stehning
authors.affiliation: University Heart Center, Department of General and Interventional Cardiology, Hamburg, Germany.
authors.forename: Ulf K
authors.initials: UK
authors.lastname: Radunski
authors.affiliation: University Hospital Cologne, Heart Center, Department of Electrophysiology, Cologne, Germany.
authors.forename: Arian
authors.initials: A
authors.lastname: Sultan
authors.affiliation: University Heart Center, Department of General and Interventional Cardiology, Hamburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schwarzl
authors.affiliation: University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
authors.affiliation: University Heart Center, Department of Cardiology - Electrophysiology, Hamburg, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Willems
authors.affiliation: University Heart Center, Department of Cardiology - Electrophysiology, Hamburg, Germany.|University Heart Center, Department of General and Interventional Cardiology, Hamburg, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Muellerleile
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D016275:Atrial Function; D064752:Atrial Remodeling; D017115:Catheter Ablation / Q000009:adverse effects*; D002908:Chronic Disease; D002921:Cicatrix / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D012086:Reoperation / Q000009:adverse effects; D016896:Treatment Outcome
keywords: atrial function; atrial scar; catheter ablation; persistent atrial fibrillation