High-density mapping of Koch’s triangle during sinus rhythm and typical AV nodal reentrant tachycardia: new insight

High‐density mapping of Koch's triangle during sinus rhythm and typical atrioventricular nodal re‐entrant tachycardia, integrated with direct recording of atrio‐ventricular node structure potential

“…Interestingly, the tachycardia cycle length coverage in the present study was 100%, as opposed to 32% in our previous study, and the ratio between the portion of the cycle covered by nodal structure potentials and the tachycardia cycle averaged 48%, with almost all patients (98%) showing a ratio of more than 30%. 3 These findings suggest that a large part of the tachycardia circuit is made up of nodal structures, which constitutes the most important difference from the previous studies, in which nodal potentials were not recorded. Moreover, in all patients, we found that the TT area acted as a zone of slow conduction, block or pseudoblock; indeed, we never ascertained the presence of a lower common pathway, suggesting that the circuit could use the extra-nodal FP and the atrial myocardium in a retrograde direction, while in an anterograde direction it could involve the RINE at the septal tricuspid infundibulum and the HB, possibly via the LNB (the existence of which, however, is controversial in humans).…”

“…2 One reason for this is the lack of human studies recording the electrical activity of the compact AVN and its extensions, which represent the diastolic interval in the tachycardia cycle; in addition, filter settings, electrode size and spacing, and signal amplification have been subject to technological limitations. 3 We recorded the AVN potential for the first time in humans in vivo and were able to characterize up to 100% of the whole AVNRT circuit.…”

“…However, although AVNRT has been extensively studied, our understanding of its exact mechanism, precise anatomical site and the pathways involved in the circuit sustaining the arrhythmia is still incomplete 2 . In our previous study of electrical activity in Koch's triangle (KT) during slow‐fast AVNRT, 3 the activation map covered less than 50% of the tachycardia cycle length; we were therefore able to record only a small portion of the AVNRT circuit in KT. The reason for this is probably that most of the circuit consists of slow action potential cells and therefore cannot be recorded by technical tools used in our previous study; alternatively, that part of the circuit may not be in the right atrium (RA).…”

Three‐dimensional electroanatomically guided slow pathway elimination is associated with procedural improvements and clinical benefit in atrioventricular node reentrant tachycardia patients

“…Notably, SP elimination was achieved in 640/1204 (53.1%) of patients, a highly similar rate to that observed in the conventional arm of our study (52.4%). In contrast, in a recent series of 45 AVNRT patients undergoing high‐density mapping of the Koch triangle, SP elimination was reported in all patients to be associated with freedom from recurrence in all cases after 12 months of follow‐up 17 . In our EAM‐based strategy, the goal of SP elimination was achieved in 95% of cases even without the advantage of high‐density mapping.…”

“…In contrast, in a recent series of 45 AVNRT patients undergoing high‐density mapping of the Koch triangle, SP elimination was reported in all patients to be associated with freedom from recurrence in all cases after 12 months of follow‐up. 17 In our EAM‐based strategy, the goal of SP elimination was achieved in 95% of cases even without the advantage of high‐density mapping. The EAM strategy focusing on SP elimination was characterized by improved procedural parameters despite the increased duration of the whole procedure.…”