title: [Clinical and electrophysiological characteristics of patients with atrioventricular nodal reentry tachycardia who underwent slow pathway ablation].
abstract: BACKGROUND
  AV nodal reentry tachycardia (AVNRT) is the most common cause of paroxysmal supraventricular tachycardia. Radiofrequency ablation is today the treatment of choice.
  
  
  OBJECTIVE
  To report our experience in patients who underwent slow pathway ablation.
  
  
  METHODS
  Fifty six consecutive patients (68% female, mean age 43 years old) that underwent slow pathway ablation are reported.
  
  
  RESULTS
  Sixty four percent of patients had failed drug therapy. During electrophysiological study, AVNRT was induced in 55 patients. Isoproterenol was required for induction in 36%. Programmed atrial stimulation revealed dual AV nodal pathway in only 64% of the patients; 29% had AVNRT with single nodal curve and 7% only prolongation of AH interval. The slow pathway was ablated in 55 patients. One patient refused ablation because of risk of AV block. All patients had immediate success post ablation. Sixty four percent of patients persisted with partial evidence of dual curve manifested by sudden AH prolongation and single echoes.
  
  
  CONCLUSIONS
  Isoproterenol is essential for ruling out AVNRT, since 29% of the patients had baseline single nodal curve and in only 64% was tachycardia induced without isoproterenol. Persistence of residual dual physiology does not rule out the success of ablation.
authors.affiliation: Laboratorio de Electrofisiología Cardíaca, Departamento de Enfermedades Cardiovasculares, Facultad de Medicina, Pontificia Universidad Católica de Chile.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Charme
authors.forename: Marianella
authors.initials: M
authors.lastname: Seguel
authors.forename: Rolando
authors.initials: R
authors.lastname: González
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002316:Cardiotonic Agents / Q000008:administration & dosage; D017115:Catheter Ablation; D002648:Child; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D007545:Isoproterenol / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000188:drug therapy / Q000503:physiopathology* / Q000601:surgery
chemical_list: D002316:Cardiotonic Agents; D007545:Isoproterenol