Catheter Ablation -> SVT/AVNRT/WPW/AT: -> Ablation Techniques D-PO05 - Poster Session V (ID 39) Poster

D-PO05-156 - The Role Of The Minimum Hv Interval And Antegrade His Activation Pattern For Discrimination Of Fasciculo-ventricular Pathways From Atrioventricular Pathways (ID 1281)


Background: Fasiculo-ventricular pathways (FVP) are rare infra-Hisian accessory pathways (AP) that dictates an antegrade His (AG) activation (AG) and an HV > 0 milliseconds (ms).
Objective: Assess the role of 2 additional criteria that can aid in the diagnosis of FVP.
Methods: The records of all patients with manifest preexcitation (Pxt) referred for Radiofrequency ablation (RFA) between 2017-19 were reviewed. The intracardiac electrograms were examined for baseline HV interval measured to the earliest -surface or intracardiac ventricular activation, the His activation pattern , and successful AP ablation site. FVP diagnosis was based on the absence of progressive preexcitation and preexcited junctional beats.
Results: A total of 63 patients were identified, 59 had Atrioventricular pathways (AVP) that were localized to the left ventricular free wall (Lt), right ventricular free wall (Rt), posteroseptal (PS), and anteroseptal (AS) in 29, 10, 15 and 5 patients respectively, whereas 4 patients had FVP. The HV interval median and range values in each patient group were: FVP 18 (15 to 22), Lt 4 (-44 to 30), Rt -12.5 (-46 to 23), PS 7 (-60 to 22), and AS -15 (-40 to 0). AG His activation was seen in all FVP. Retrograde His activation (RG) that is inconsistent with FVP was seen in 12/59 patients (20%) with AVP (AS, PS or Rt) whereas 51 of all AVP patients had an HV < 15 ms (figure 1). The HV cutoff of ≥ 15 ms combined with AG-His pattern was absent in 51/59 patients with AVP indicating a specificity rate of 86.4% in this group of patients.
Conclusion: A baseline minimum HV interval of ≥ 15 ms in addition to AG His activation pattern can be of use in discriminating FVP from AVP especially in those with septal, and right side AP.