PO-05-096 PROGNOSTIC VALUE OF NEAR-FIELD ELECTROGRAMS AT CRITICAL ABLATION SITES DURING VENTRICULAR TACHYCARDIA ABLATION

Electrogram (EGM) annotation during VT is challenging due to complexity of EGMs and difficulty in distinguishing far-field near-field (NF) EGMs. EGM frequency increases with greater proximity the recording electrode. The prognostic value high-frequency at critical ablation sites unknown. utility recently developed algorithms annotate local 3D mapping (Ensite X, Abbott, Inc.) absence high for may suggest that interest deep or remote from To investigate ablation. Consecutive patients scar-related undergoing catheter (RFA) were analyzed. High density substrate maps created presenting ventricular rhythm using a High-definition multi-electrode (HD Grid, Inc.). Critical induced identified based on pace-mapping, activation mapping, entrainment termination RFA. Substrate retrospectively analyzed NF EGM. highest within 5mm site was Thirty-four ablated twenty-two patients, 14 (64%) ischemic cardiomyopathy, age 65±10 years LVEF 33±13 %. recurred 9 (41%). peak recurrence significantly lower than without (192 vs 397 Hz; p=0.01). Cox regression analysis shows statistically significant higher risk have when below median (HR 5.09, 95% C.I 1.05-24.68, p=0.04). Area under receiver operator characteristic curve as predictor 0.81, < 286 Hz providing 89% sensitivity 69% specificity recurrence. Low measured by software identify A finding low apparent implies successful require additional including consideration epicardial venous localize better true techniques provide deeper