title: [Interventional treatment of typical atrial flutter].
abstract: OBJECTIVE
  To inform the efficacy and safety of the interventional treatment of typical atrial flutter (AFL). AFL is a common arrhythmia that has a characteristic pattern on 12-lead ECG. The unique endocardial anatomy of the right atrium, with its many orifices and distinct structures provides anatomic barriers around which reentry could occur, likely explains the consistency of AFL from patient to patient. Much of our current understanding of the role of barriers in AFL has been from animal models. Using multisite endocardial mapping in patients with AFL, activation in the right atrium spreads superiorly from the coronary sinus ostium, up the septum and down the lateral right atrial wall (counterclockwise rotation of typical flutter and clockwise in reverse typical AFL).
  
  
  METHODS
  A critical area of slow conduction was identified between the coronary sinus ostium, tricuspid valve ring, and inferior vena cava (the cavotricuspid isthmus). Entrainment has also been used to interrogate the AFL circuit. Concealed entrainment demonstrates that typical AFL is a reentrant arrhythmia and it has been demonstrated in the area of cavotricuspid isthmus. AFL is an arrhythmia that can be cured by catheter ablation of the tricuspid valve-inferior vena cava isthmus. The aim of catheter ablation for typical AFL is to create a complete and stable bidirectional cavotricuspid isthmus block. Ablation is performed during AFL or sinus rhythm, using either an 8/10 mm tip catheter or an irrigated tip catheter.
  
  
  RESULTS
  After ablation, assessment of cavotricuspid isthmus conduction is performed periodically to confirm a complete and stable bidirectional block. With this primary end-point, the long-term efficacy has increased to >90% with low recurrence rate.
  
  
  CONCLUSIONS
  Ablation of AFL is safe and effective, improved quality of life and has a minimal risk of adverse effects. Catheter ablation is now considered as alternative first line therapy for all those with symptomatic sustained typical AFL.
authors.affiliation: Servicio de Electrofisiología, Hospital de Cardiología, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social. enve@prodigy.net.mx
authors.forename: Enrique
authors.initials: E
authors.lastname: Velázquez-Rodríguez
mesh_terms: D001282:Atrial Flutter / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation; D006801:Humans