title: Independent ablation of retrograde and anterograde accessory connection conduction at the atrial and ventricular insertion sites: evidence supporting the impedance mismatch hypothesis for unidirectional block.
abstract: BACKGROUND
  The impedance mismatch hypothesis has been proposed as one of the mechanisms responsible for accessory connection conduction block.
  
  
  RESULTS
  We describe a case in which retrograde conduction across a posteroseptal accessory connection was ablated at the atrial insertion site in the coronary sinus os, whereas anterograde conduction was ablated at the ventricular insertion site in the left ventricle.
  
  
  CONCLUSIONS
  The evidence supports the impedance mismatch concept as the cause of unidirectional conduction block and shows that the distal junction between the accessory connection and the myocardium is more vulnerable to ablation.
authors: Division of Cardiology, University Hospitals of Cleveland, Case Western Reserve University, Ohio 44106.
authors: J M
authors: JM
authors: Vijgen
authors: M D
authors: MD
authors: Carlson
mesh_terms: D000328:Adult; D001283:Atrioventricular Node / Q000503:physiopathology; D017115:Catheter Ablation; D004562:Electrocardiography; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D014927:Wolff-Parkinson-White Syndrome / Q000503:physiopathology* / Q000601:surgery