Catheter Ablation -> Ventricular Arrhythmias -> Experimental methods D-PO06 - Poster Session VI (ID 26) Poster

D-PO06-088 - A More Definitive Method To Map Arrhythmogenic Substrate For VT Ablation (ID 657)


Background: LAVA potentials are considered targets for VT substrate ablation. However LAVA is generally of low amplitude and may be obscured by far field electrograms (egms). Bipole voltage along the direction of electric field produces maximal amplitude, potentially rescuing minute potentials that may be under recognized or under differentiated from the far field ventricular egms.
Objective: To test the hypothesis that assessment of LAVA from egms derived from omnipolar maximal voltage (LAVAmax) provides larger amplitude fractionated egms and greater differentiation from traditional bipoles as derived from regular grid arrays.
Methods: LAVA egms were identified from 5 diseased isolated human hearts mapped with a 14 x 8 rectangular grid electrode array. A total of 288 fractionated bipolar egms and corresponding omnipolar egms were included for analysis. Performance was evaluated with Clinical Benefit Proportion (CBP). CBP is calculated as the proportion of sites with bipolar egms that would be under detected at specified thresholds of 0.5, 0.4, 0.3 and 0.2 mV that LAVAmax would consider above the same thresholds.
Results: LAVAmax always have higher amplitude than the largest corresponding bipolar egms (0.74 ± 0.03 mV vs. 0.68 ± 0.03 mV, p < 0.001). Average CBP for all thresholds was 0.48, suggesting nearly half of the fractionated egms at any threshold detectable with LAVAmax may not be detected with bipolar egms.
Conclusion: This study found E-field methodology reveals LAVA potentials that may be missed using traditional bipolar mapping methods. More studies are necessary to see if mapping LAVA with contemporary grid catheters will lead to improved outcomes.