High-density Mapping of a Posteroseptal Accessory Pathway Using Open-window Mapping

Use of High-density Mapping to Ablate a Wide Accessory Pathway and Mahaim Fiber in a Patient with Ebstein’s Anomaly

“…Open-window mapping has recently been found to be useful in aiding ablation of conventional accessory AV pathways. 6 – 8 In Ebstein’s anomaly, the AV annulus can be poorly defined due to the adherence of the tricuspid valve tissue to the ventricular myocardium, creating a zone of atrialized ventricular myocardium. This zone often has low-voltage signals that can be difficult to interpret and makes definition of the true electrical AV annulus difficult.…”

Open Window Mapping of Accessory Pathways: A Literature Review and Practical Guide

“…9 Subsequently, the OWM technique has been further reported in case reports. [14][15][16] OWM has significant advantages over conventional mapping techniques because there is no need to identify atrial, ventricular or pathway EGMs, which can be difficult to see in some cases, particularly with widely spaced bipolar mapping ablation catheters, and can depend on operator experience. Rather, in OWM, both atrial and ventricular EGM signals are included in the WOI and there is automatic algorithm-driven detection of local signals demonstrating the maximum change in voltage over time (dV/dt).…”