Ablation of a Symptomatic Spontaneous Automatic Focus Arising from an Atriofascicular Fiber

Atriofascicular accessory pathways (AP), often referred to as Mahaim pathways, are uncommon electrical connections that most often course along the lateral right atrium and insert within the distal right bundle branch (RBB). Pathognomomic electrophysiological characteristics are well described, including unidirectional anterograde conduction with AV node–like decremental properties. Reported targets for ablation include the site of the Mahaim potential along the atrial aspect of the tricuspid annulus or at the ventricular insertion site of the pathway.