title: Radiofrequency catheter ablation of atrial fibrillation guided by spectral mapping of atrial fibrillation nests in sinus rhythm.
abstract: BACKGROUND
  Two types of myocardia can be observed through the endocardial spectral mapping (SM) in sinus rhythm: the compact type with a smooth spectrum and the fibrillar type with a segmented spectrum (atrial fibrillation nests). During the atrial fibrillation (AF), the compact type has an organized activation and low frequency (passive), whereas the fibrillar type has a rather disorganized activation and high frequency (active/resonant), with both being activated by high-frequency sustained tachycardia--the background tachycardia (BT).
  
  
  OBJECTIVE
  To describe the treatment of AF by the ablation of the AF nests and BT.
  
  
  METHODS
  1) Catheter ablation of the AF nests with RF [4/8 mm-60 masculine/30-40 J/30s] guided by SM in sinus rhythm, outside the pulmonary vein; 2) atrial stimulation -300 ppm; 3) Additional ablation of the AF nests if AF is induced; 4) Focal ablation if BT and/or Flutter is induced; 5) Clinical follow-up+ ECG+ Holter.
  
  
  RESULTS
  A total of 50+/-18 AF nests/patient were treated. After 11.3+/-8 m, 81 patients (88%) did not present AF (28.3% with antiarrhythmic drugs). After the ablation of the AF nests, AF was not reinduced in 61 patients (71%) and BT was induced and treated in 24 patients (26%). There were two episodes of pericardial bleeding (1 treated clinically and 1 surgically), caused by sheaths that are no longer used
  
  
  CONCLUSIONS
  The SM in sinus rhythm can be used in the ablation of AF nests. During the AF, the AF nests present a reactive-resonant pattern and the compact myocardium is passive, stimulated by the high frequency of the BT. After the ablation of the AF nests and the BT, it was not possible to reinduce the sustained AF. The Ablation of AF nests outside the pulmonary veins showed to be safe and highly effective in the cure and/or clinical control of the AF.
authors: Hospital do Coração (HCor) and Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brazil. jcpachon@hotmail.com
authors: José Carlos Pachón
authors: JC
authors: Mateos
authors: Enrique I Pachón
authors: EI
authors: Mateos
authors: Tasso J
authors: TJ
authors: Lobo
authors: Maria Zélia C
authors: MZ
authors: Pachón
authors: Juán Carlos Pachón
authors: JC
authors: Mateos
authors: Denilda Queiroz V
authors: DQ
authors: Pachón
authors: Remy Nelson A
authors: RN
authors: Vargas
authors: Leopoldo S
authors: LS
authors: Piegas
authors: Adib D
authors: AD
authors: Jatene
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods* / Q000592:standards; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000601:surgery; D013610:Tachycardia / Q000503:physiopathology / Q000601:surgery*