title: Local Electrical Dyssynchrony during Atrial Fibrillation: Theoretical Considerations and Initial Catheter Ablation Results.
abstract: BACKGROUND
  Electrogram-based identification of the regions maintaining persistent Atrial Fibrillation (AF) is a subject of ongoing debate. Here, we explore the concept of local electrical dyssynchrony to identify AF drivers.
  
  
  RESULTS
  Local electrical dyssynchrony was calculated using mean phase coherence. High-density epicardial mapping along with mathematical model were used to explore the link between local dyssynchrony and properties of wave conduction. High-density mapping showed a positive correlation between the dyssynchrony and number of fibrillatory waves (R2 = 0.68, p<0.001). In the mathematical model, virtual ablation at high dyssynchrony regions resulted in conduction regularization. The clinical study consisted of eighteen patients undergoing catheter ablation of persistent AF. High-density maps of left atrial (LA) were constructed using a circular mapping catheter. After pulmonary vein isolation, regions with the top 10% of the highest dyssynchrony in LA were targeted during ablation and followed with ablation of complex atrial electrograms. Catheter ablation resulted in termination during ablation at high dyssynchrony regions in 7 (41%) patients. In another 4 (24%) patients, transient organization was observed. In 6 (35%) there was no clear effect. Long-term follow-up showed 65% AF freedom at 1 year and 22% at 2 years.
  
  
  CONCLUSIONS
  Local electrical dyssynchrony provides a reasonable estimator of regional AF complexity defined as the number of fibrillatory waves. Additionally, it points to regions of dynamical instability related with action potential alternans. However, despite those characteristics, its utility in guiding catheter ablation of AF is limited suggesting other factors are responsible for AF persistence.
authors: Department of Cardiology-Electrophysiology, University Hospital Hamburg, University Heart Center, Hamburg, Germany.
authors: Pawel
authors: http://orcid.org/0000-0001-8440-654X
authors: P
authors: Kuklik
authors: Department of Cardiology-Electrophysiology, University Hospital Hamburg, University Heart Center, Hamburg, Germany.
authors: Benjamin
authors: B
authors: Schäffer
authors: Department of Cardiology-Electrophysiology, University Hospital Hamburg, University Heart Center, Hamburg, Germany.
authors: Boris A
authors: BA
authors: Hoffmann
authors: Flinders University School of Medicine and Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia.
authors: Anand N
authors: AN
authors: Ganesan
authors: Department of Cardiology-Electrophysiology, University Hospital Hamburg, University Heart Center, Hamburg, Germany.
authors: Doreen
authors: D
authors: Schreiber
authors: Department of Cardiology-Electrophysiology, University Hospital Hamburg, University Heart Center, Hamburg, Germany.
authors: Julia M
authors: JM
authors: Moser
authors: Department of Cardiology-Electrophysiology, University Hospital Hamburg, University Heart Center, Hamburg, Germany.
authors: Ruken Ö
authors: RÖ
authors: Akbulak
authors: Department of Cardiology-Electrophysiology, University Hospital Hamburg, University Heart Center, Hamburg, Germany.
authors: Arian
authors: A
authors: Sultan
authors: Department of Cardiology-Electrophysiology, University Hospital Hamburg, University Heart Center, Hamburg, Germany.
authors: Daniel
authors: D
authors: Steven
authors: Department of Cardio-thoracic Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors: Bart
authors: B
authors: Maesen
authors: Department of Physiology, Maastricht University, Maastricht, The Netherlands.
authors: Ulrich
authors: U
authors: Schotten
authors: Department of Cardiology-Electrophysiology, University Hospital Hamburg, University Heart Center, Hamburg, Germany.|DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany.
authors: Christian
authors: C
authors: Meyer
authors: Department of Cardiology-Electrophysiology, University Hospital Hamburg, University Heart Center, Hamburg, Germany.|DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany.
authors: Stephan
authors: S
authors: Willems
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D003131:Combined Modality Therapy; D056149:Epicardial Mapping / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D010865:Pilot Projects; D016896:Treatment Outcome