Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Mapping & Imaging D-PO04 - Poster Session IV (ID 15) Poster

D-PO04-176 - Identifying Substrate For Atrial Tachycardia With A High-density Mapping Catheter That Accounts For Wavefront Directionality (ID 1222)


Background: Ultra high-density mapping allows for visualization of low noise bipolar voltages, but a known limitation is wavefront directionality. This can be problematic when identifying substrate for atrial tachycardia (AT). Despite advances in high-density catheters, successful AT ablation remains challenging. A new ultra high-density closed-frame, four-spline grid catheter containing 16 x 1mm electrodes spaced equidistantly along and across the spines, enables simultaneous assessment of adjacent, orthogonal electrograms (EGM).
Objective: To investigate if ultra-high-density mapping with simultaneous assessment of orthogonal electrograms can identify AT substrate with a high degree of accuracy.
Methods: Patients undergoing left atria (LA) mapping for post-atrial fibrillation AT were enrolled. The Advisor HD Grid catheter (Abbott) was used to create LA geometry, activation & voltage maps.
Results: 17 consecutive patients underwent AT catheter ablation; all were macro re-entrant with a mean cycle length of 297.6±65.1ms The average time to create a map was 16.6±6.8mins. The mean points collected and used were 12220 ± 7259 and 2134± 739. RF time and number of energy applications were 811.3±708.1s and 76.1 ±62.8 respectively. Ablation terminated AT in 94.0% (CI 95%: 81.2-106.6) of cases. Time taken from the onset of ablation to termination was a mean of 7.2±5.8s. Mean AT EGM amplitude & width were 0.21±0.07mV & 56.6±21.3ms respectively.
Conclusion: Ultra-high-density mapping with simultaneous detection of orthogonal EGMs, allows for quick & accurate identification of slow conduction zones responsible for an AT circuit, with ablation terminating AT in the majority of cases.