B-PO05-206 OMNIPOLAR MAPPING CLARIFIES AMBIGUOUS ATRIAL TACHYCARDIA ISOCHRONAL MAP IN PATIENT WITH TETRALOGY OF FALLOT

Abstract

Atrial Tachycardia (AT) in adult congenital heart disease (ACHD) result from complex anatomy due to ACHD and surgical repair. Multiple scar areas harbor slow conduction, delayed activation and reentry circuits, limiting standard bipolar mapping of local activation time (LAT). New mapping technique utilizing orthogonal bipoles to construct electrograms (EGM) in 360 degrees, Omnipolar Mapping (OM), displays wavefront vector map as arrows utilizing 16 pole grid-like catheter (HD Grid), displayed as static map, or live map of grid OM as it moves throughout chamber, for real-time wavefront propagation display. N/A 43M repaired Tetralogy of Fallot underwent mapping and ablation for AT. LAT with Abbott Precision system and HD Grid showed large low voltage area (LVA) at lateral right atrium (RA). AT1 mapped to the superior scar border. Radiofrequency (RF) changed cycle length (CL) from 200ms to 240 ms. Remapping showed confusing LAT, with multiple “early” areas (Fig 1a). Adjusting mapping window displayed more focal origin (FO) (Fig 1b) on RA septum (AT2). RF here again slowed tachycardia to 315ms. Remapping showed AT3 was typical flutter. Offline analysis with research software allowed for OM. AT2 Static vector map showed FO “starburst” pattern (Fig 1a,b): arrows pointing outward from FO (successful RF, brown circle). “Real time” HD Grid vector map displayed this pattern at FO within first 6 minutes of mapping (Fig 1c). Vectors pointed away from FO when HD Grid positioned adjacent to the FO (Fig 1d). This difficult case illustrates HD Grid and OM may offer superior efficiency and less ambiguity for mapping of arrhythmias in complex substrates.