Mapping Atrial Fibrillation Dispersion Regions

We used a single transseptal sheath. Mapping was performed in AF. For patients in sinus rhythm (SR), AF was induced by rapid atrial pacing using the coronary sinus (CS) catheter (from 500 to 180 ms). When AF was not inducible, isoproterenol (baseline dose: 2.4 mg/h, increased in 0.2 mg increments to reach a sinus rate > 100 beats/min) was infused. Baseline mapping in both atria was performed during AF with the PentaRay multispline catheter (Biosense Webster, Diamond Bar, CA, USA, 2-6-2 mm spacing) sequentially positioned in various regions of the RA and LA. At each location, the catheter was maintained in a stable position for a minimum of 2.5 s. As previously described [3 (link)], the operator conducted a mapping of dispersion regions. Briefly, dispersion corresponded to clusters of electrograms (EGMs), either fractionated or non-fractionated, that displayed interelectrode time and space dispersion at a minimum of three adjacent bipoles such that activation spread over all the AFCL. Dispersion regions were manually tagged on the 3D CARTO navigation system.