Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Mapping & Imaging D-PO01-NC - Non-CME Poster Session (ID 14) Poster

D-PO01-NC-15 - Quantifying Bipolar Bias In Atria And Guidance To Map Physiologically Relevant Low Voltage (ID 1482)

  D. Deno: Salary from Employment (Commercial Interest) - Abbott.


Background: The threshold for atrial low voltage (scar) is variable and bipoles perpendicular to wavefront directions can register low voltage. It is unknown what proportion of scar map points determined regardless of orientation are truly low voltage and not victims of bipolar bias. A uniformly spaced grid array catheter with orthogonally directed bipole pairs permits comparisons among 3 methods to report voltage: bipoles in all directions (All Bi), the maximum of an orthogonal pair (HD Wave SolutionTM), and Omnipolar Technology’s maximum over any orientation (OT Vmax).
Objective: Compare traditional All Bi voltage map points with those of HD Wave and OT Vmax and devise a strategy to obtain more a physiologically relevant atrial scar maps.
Methods: HD Wave and OT Vmax were compared against All Bi in 21 atrial voltage maps from 4 anesthetized swine and 5 humans in arbitrary orientations compared to wavefronts. Exported maps were processed from 9222 beats and bipole electrode pairs. Improvement was quantified using the Clinical Benefit Proportion (CBP). CBP is the proportion of points with All Bi voltage less than scar threshold X that HD Wave or OT Vmax consider as having voltage > X.
Results: As thresholds decreased from 1 to 0.1 mV, CBPs rose significantly from 26 to 50% (HD Wave) and 29 to 57% (OT Vmax) (Mixed effects model, Fischer pairwise comparisons, p < 0.05). At all scar thresholds, OT Vmax CBP exceeded that of HD Wave by a mean of 4.6% (p < 0.01).
Conclusion: Use of a grid array catheter in conjunction with HD Wave or OT Vmax algorithms improves atrial scar designation, markedly so at low scar thresholds. Orientation aware voltage mapping potentially allows for better determinations of scar borders.