LAUSR

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac magnetic resonance has demonstrated to accurately identify voltage conduction channels and it is nowadays an important tool to analyze the arrhythmic substrate, to predict ventricular tachycardia (VT) events and to aid VT ablation. The characteristics of CMR channels (CMR-CCs) that predicts the presence of deceleration zone (DZ) have not been explored. Methods Forty-four consecutive patients with scar-related VT undergoing ablation after CMR (October 2018-July 2021) were included (medium age 64.8±11.6 years; 95.5% male; 70.5% ischemic heart disease, mean ejection fraction of 32.3±7.8). Characteristics of CMR-CCs were analyzed and correlation with DZs both in baseline maps and remaps were performed. Patients were prospectively followed for VT recurrence for one year. Results Overall, 129 automatically detected CMR-CCs were analyzed (2.89±1.83 per patient; length: 52.72±65.44mm (0.18–376.73), CC mass: 1.76±2.46grams (0.01–14.59); protectedness 19.02±24.51% (0.01–143.51)). Overall, 73.6% of CMR-CCs were associated with a DZ: 58.1% CMR-CCs in baseline map and 15.5% with a DZs not observed initially but in remaps. The univariate analysis showed that channels associated with DZs were longer (61.83±73.43 vs. 29.96±32.55, OR 1.01, p0.004), with higher border zone mass (2.02±2.75 vs. 1.09±1.44, OR 1.28, p0.031) and more protectedness (21.90±27.23 vs. 11.46±14.20, OR1.02, p0.036). VT recurrence after one-year follow up was 21.95%. Conclusions Pre ablation CMR can accurately identify channels that correlates with DZs that could be targets for ablation, especially those CMR-CCs with higher length, border zone mass and protectedness. Additionally, some channels not related with DZ in the first map have a clear DZ after abolishing the first region of slow conduction, suggesting a very useful role of CMR to detect potential DZs. Fig 1 Fig 2