Basic/Translational Science -> Computer Modeling/Simulation D-PO02 - Poster Session II (ID 47) Poster

D-PO02-027 - Investigating The Ability Of Substrate Mapping Techniques To Identify Ventricular Tachycardia Circuits Using Computational Modelling (ID 986)

Abstract

Background: Identification of targets for ablation of ventricular tachycardias (VTs) in the infarcted heart remains challenging, often requiring arrhythmia induction to delineate the reentrant circuit. If induction is not possible, substrate mapping can still be performed to uncover vulnerable substrates; however, VT recurrence remains common.
Objective: To use computer simulations to compare the ability of different electroanatomical maps to identify the VT exit site during pacing.
Methods: An MRI-based computational model of the porcine post-infarction heart was constructed to simulate VT and paced rhythm. Electroanatomical maps were constructed based on endocardial electrogram features and the reentry vulnerability index (RVI - a metric combining activation, AT, and repolarization timings to identify tissue susceptibility to reentry). Potential ablation targets were compared for highest or lowest 5% values. The minimum distance, d, between the VT exit site and the targets was measured.
Results: The RVI performed better than the other metrics at detecting the VT exit site (Figure). The minimum distance between sites of lowest RVI and the exit site was 3.2mm compared to 13.1mm and 15.9mm in AT and voltage maps. Since scar transmurality was not homogeneous, parameters derived from all signals (including dense scar regions) were used to construct the maps, improving the performance of the RVI significantly.
Conclusion: Among all metrics, the RVI identified the vulnerable region closest to VT exit site suggesting that activation-repolarization metrics may improve the detection of pro-arrhythmic regions without inducing VT even in infarcts with non-transmural scars.
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