title: Fasciculoventricular pathways: clinical and electrophysiologic characteristics of a variant of preexcitation.
abstract: Fasciculoventricular Fibers.
  
  
  BACKGROUND
  Fasciculoventricular tracts are considered a rare form of ventricular preexcitation. Few fasciculoventricular pathways have been reported, and none have been linked to a reentrant tachycardia.
  
  
  RESULTS
  Four patients with fasciculoventricular bypass tracts underwent electrophysiologic evaluation. Two patients had a single fasciculoventricular pathway, one that inserted anteroseptally and the other in the left ventricle. Two patients also had an AV bypass tract, with anterograde conduction over the fasciculoventricular pathway during orthodromic AV reentrant tachycardia. After ablation of the AV pathways, the ECG during sinus rhythm and the electrophysiologic study showed ventricular preexcitation due to a fasciculoventricular bypass tract inserting into the right ventricle. Adenosine triphosphate was helpful in the diagnostic process.
  
  
  CONCLUSIONS
  Electrophysiologists should be able to make the differential diagnosis between a fasciculoventricular bypass tract and an anteroseptal accessory pathway to preclude potential harm to the AV conduction system if a fasciculoventricular pathway is targeted for catheter ablation.
authors.affiliation: Department of Arrhythmia and Electrophysiology, Biocor Instituto, Nova Lima, Brazil. eduardosternick@aol.com
authors.forename: Eduardo Back
authors.initials: EB
authors.lastname: Sternick
authors.forename: Luiz Márcio
authors.initials: LM
authors.lastname: Gerken
authors.forename: Mário O
authors.initials: MO
authors.lastname: Vrandecic
authors.forename: Hein J J
authors.initials: HJ
authors.lastname: Wellens
mesh_terms: D000293:Adolescent; D000328:Adult; D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011226:Pre-Excitation Syndromes / Q000145:classification* / Q000175:diagnosis*; D011227:Pre-Excitation, Mahaim-Type / Q000145:classification / Q000175:diagnosis; D017180:Tachycardia, Ventricular / Q000145:classification* / Q000175:diagnosis*; D014927:Wolff-Parkinson-White Syndrome / Q000145:classification / Q000175:diagnosis