title: Characterization of the nodal slow pathway in patients with nodal reentrant tachycardia: clinical implications for guiding ablation.
abstract: OBJECTIVE
  Nodal slow pathway ablation is the treatment of choice for nodal reentrant tachycardia. No demographic, anatomic, or electrophysiologic variables have been reported to predict an exact location of the slow pathway in the atrioventricular node or its proximity to the fast pathway. The purpose of this study was to analyze these variables.
  
  
  METHODS
  The study prospectively included 54 patients (17 men; mean age, 55 [16] years) who had undergone successful slow pathway ablation. The refractory periods of both pathways and their differential conduction time were measured, and calculations were performed to obtain the distance from the His-bundle region (location of the fast pathway) to the coronary sinus ostium (to estimate the anteroposterior length of the triangle of Koch) and to the slow pathway area.
  
  
  RESULTS
  The differential conduction time (139 [98] ms) did not correlate with the His-coronary sinus distance (19 [6] mm; P=.6) or the His-slow pathway distance (14 [4] mm; P=.4). When the His-coronary sinus distance was larger, the His-slow pathway distance was also larger (r=0.652; P<.01) and the anatomic correlation between the triangle dimensions and the separation between the two pathways was confirmed. In patients older than 70 years, smaller triangle sizes and a shorter distance between both pathways were observed (P<.001).
  
  
  CONCLUSIONS
  A greater anteroposterior dimension of the triangle of Koch is associated with a slow-pathway location farther from the fast pathway. In elderly patients the two pathways are closer together (higher risk of atrioventricular block).
authors.affiliation: Unidad de Arritmias, Servicio de Cardiología, Hospital del Mar, Barcelona, Spain. Electronic address: miguel.jauregui.abu@gmail.com.
authors.forename: Miguel E
authors.initials: ME
authors.lastname: Jauregui-Abularach
authors.affiliation: Unidad de Arritmias, Servicio de Cardiología, Hospital del Mar, Barcelona, Spain.
authors.forename: Victor
authors.initials: V
authors.lastname: Bazan
authors.affiliation: Unidad de Arritmias, Servicio de Cardiología, Hospital del Mar, Barcelona, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Martí-Almor
authors.affiliation: Unidad de Arritmias, Servicio de Cardiología, Hospital del Mar, Barcelona, Spain.
authors.forename: Debora
authors.initials: D
authors.lastname: Cian
authors.affiliation: Unidad de Arritmias, Servicio de Cardiología, Hospital del Mar, Barcelona, Spain.
authors.forename: Ermengol
authors.initials: E
authors.lastname: Vallès
authors.affiliation: Unidad de Arritmias, Servicio de Cardiología, Hospital del Mar, Barcelona, Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: Benito
authors.affiliation: Unidad de Arritmias, Servicio de Cardiología, Hospital del Mar, Barcelona, Spain.
authors.forename: Oona
authors.initials: O
authors.lastname: Meroño
authors.affiliation: Unidad de Arritmias, Servicio de Cardiología, Hospital del Mar, Barcelona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Bruguera-Cortada
mesh_terms: D001283:Atrioventricular Node / Q000503:physiopathology* / Q000601:surgery; D002036:Bundle of His / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome
keywords: Ablación con catéter; Catheter ablation; Nodal reentrant tachycardia; Slow pathway; Taquicardia por reentrada nodular; Triangle of Koch; Triángulo de Koch; Vía lenta