title: Ablation of left atrial tachycardia with cycle length alternans after atrial fibrillation ablation: significance of fractionated electrogram mapping.
abstract: BACKGROUND
  Atrial tachycardia (AT) with cycle length alternans occurring after atrial fibrillation ablation has not been previously described.
  
  
  METHODS
  Among 66 patients with left AT, stable AT with 2 alternating cycles was registered in 5 cases. Activation mapping of both alternating cycles was performed in all 5 patients. Entrainment and fractionated electrogram mappings were also carried out.
  
  
  RESULTS
  Among 10 AT cycles, activation maps suggested underlying mechanism of 5 cycles (50%) in 3 patients. Entrainment pacing was helpful in 2 patients (confirmed mechanism of 2 AT cycles). Catheter ablation successfully terminated AT in all 5 patients: ablation of sites with fractionated potentials in 4 patients and mitral isthmus ablation in 1 patient.
  
  
  CONCLUSIONS
  Consecutive activation mapping of both AT cycles is feasible for mechanism determination in some patients. The results of our small study suggest that fractionated electrogram-guided ablation might be a reasonable approach for termination of this type of AT.
authors.affiliation: Department of Electrophysiology and Cardiac Pacing, Almazov Federal Heart, Blood and Endocrinology Centre, Saint-Petersburg, Russian Federation. evgenymikhaylov@gmail.com
authors.forename: Evgeny
authors.initials: E
authors.lastname: Mikhaylov
authors.forename: Tamas
authors.initials: T
authors.lastname: Szili-Torok
authors.forename: Mikhail
authors.initials: M
authors.lastname: Abramov
authors.forename: Dmitry
authors.initials: D
authors.lastname: Lebedev
mesh_terms: D001281:Atrial Fibrillation / Q000150:complications* / Q000175:diagnosis / Q000601:surgery*; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013612:Tachycardia, Ectopic Atrial / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control*; D016896:Treatment Outcome