Ablation of a symptomatic spontaneous automatic focus arising from an atriofascicular fiber

An unusual ectopic ventricular rhythm in a young woman

“…As previously described, abnormal automaticity, which may range from asymptomatic slow rhythms to repetitive ectopic rhythms with an LBBB configuration, is not uncommon in Mahaim fibers (12.5% of 40 patients with atriofascicular fiber), but predominantly occurrs during radiofrequency ablation of the fiber . It is interesting that the arrhythmia complaints in our patient started during pregnancy, raising the possibility that hormonal influences played a role in the pathogenesis, which was also reported in a similar case, who developed symptomatic premature ventricular contractions during fertility treatment years after ablation of an atriofascicular fiber . The arrhythmia did continue after the delivery, remaining severe enough to decide on catheter ablation.…”

A wide QRS tachycardia with the short and long ventriculoatrial interval in the presence of an atriofascicular pathway: What is the mechanism?

“…However, the WCT with nearly simultaneous atrial activation in the region of the fast pathway of the AV node in Figure 3 was not consistent with antidromic AF pathway-related tachycardia because more atrial than ventricular activations are present. [15][16][17] [18][19][20] or longitudinal dissociation, 14,[20][21][22][23][24] AF jump, 14,24 development of the retrograde right bundle branch block, [25][26][27][28][29] and AF automaticity 23,[30][31][32][33][34][35][36][37][38] should be kept in mind in the differential diagnosis of changes in VA interval during the AF related tachycardia. In Figure 3, the AF automaticity was fully preexcited during WCT, whereas it was gone down via the AV node with the appearance of antegrade His signal.…”

Multiple QRS Morphologies

“…They exhibit features similar to the AVN, with decremental properties and histologic evidence of cells resembling AVN tissue. Some atriofascicular fibers demonstrate automaticity, 1 , 2 which can manifest as single premature beats or salvos that appear to be of ventricular origin, and they have been observed spontaneously and can occasionally trigger antidromic tachycardia. 3 …”