title: [Catheter ablation of accessory pathways with low energy. Results in 40 consecutive patients].
abstract: OBJECTIVE
  To evaluate the results of direct current catheter ablation of accessory pathways by mean of a new low energy power source.
  
  
  METHODS
  Catheter ablation was performed in 40 consecutive patients (23 male, mean age 31 +/- 11 years) with accessory atrioventricular pathways (AP) using a low energy DC power source. The electrophysiologic study and AP ablation were performed in the same procedure by endocardial approach using non-deflectable 6F bi, tri, or quadripolar electrodes.
  
  
  RESULTS
  AP was located at left free wall (LFW) in 22 patients (55%), posteroseptal (PS) in 11 patients (27.5%), anteroseptal (AS) in 5 patients (12.5%) and right lateral (RL) in 2 patients (5.0%). A mean of 7.7 +/- 7 catodal shocks of 5-75 (20) joules (J) was delivered in 1.45 +/- 7 sessions, with a mean cumulative energy of 178 +/- 213J per patient. The mean values of number of shocks, number of sessions and cumulative energy per patient were lower in LFW AP ablation than in other positions (5 +/- 4 x 11 +/- 8 - p = 0.008; 1.1 +/- 0.3 x 1.8 +/- 0.9 - p = 0.008 and 118 +/- 150 x 260 +/- 245 - p = 0.03). The mean CK-MB rise was 18.5 +/- 7.8U/1. Three patients (7.5%) presented hemopericardium after PS AP ablation and in 1 patient (2.5%), a PS AP (paranodal pathway) ablation resulted in total atrioventricular block. During a follow-up of 9.5 +/- 4 months AP was absent in 28 (70%) patients; 18/22 (82%) with LFW AP, 6/11 (54%) with PS AP, 3/5 (60%) with AS AP and 1/2 (50%) with RL-AP, (p = 0.10).
  
  
  CONCLUSIONS
  Low energy DC ablation is effective for AP ablation. The results are related with AP position.
authors.affiliation: Instituto do Coração do Hospital das Clínicas, FMUSP.
authors.forename: M
authors.initials: M
authors.lastname: Scanavacca
authors.forename: E
authors.initials: E
authors.lastname: Sosa
authors.forename: E R
authors.initials: ER
authors.lastname: Cruz
authors.forename: A
authors.initials: A
authors.lastname: Scatolini Neto
authors.forename: E
authors.initials: E
authors.lastname: Nadalin
authors.forename: F
authors.initials: F
authors.lastname: Yulita
authors.forename: J C
authors.initials: JC
authors.lastname: Piccioni
authors.forename: F
authors.initials: F
authors.lastname: Consolim
authors.forename: G
authors.initials: G
authors.lastname: Bellotti
authors.forename: F
authors.initials: F
authors.lastname: Pileggi
mesh_terms: D000293:Adolescent; D000328:Adult; D017115:Catheter Ablation / Q000379:methods*; D004594:Electrophysiology; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000002:abnormalities / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013610:Tachycardia / Q000601:surgery
vernacular_title: Ablação por cateter de vias acessórias com choques de baixa energia. Resultados em 40 pacientes consecutivos.