Abstract 16824: Fully Validated Mri-Based Computational Models of Swine Hearts With Post-Infarction Ventricular Tachycardia
Background: Identification of the optimal ablation sites in hearts with infarct related ventricular tachycardia (VT) remains difficult to achieve with the current catheter based mapping techniques. Limitations arise for ambiguities in determining the location(s) of reentrant pathways arising from the infarct zone. The goal of this study was to develop fully validated, individualized computer models of infarcted swine hearts that can be used to predict the characteristics of infarct related VT and where it is localized, and thus the optimal targets of ablation.
Methods: In 5 pigs 10 weeks post infarction, VT was induced via programmed electrical stimulation. Epicardial sock electrodes were used to record electrical activity. The heart was then explanted and imaged using contrast enhanced MRI. The images were segmented to identify myocardium, semi viable gray zone (GZ), and scar based on pixel intensity. GZ was modeled as a region with longer APD and increased anisotropy, and scar as passive tissue. VT induction was simulated in the models following the experimental protocol.
Results: All 5 pigs were inducible for VT with mean cycle length of 186±30 ms. In 3 pigs VT manifested as centrifugal activity; the other 2 pigs had epicardial reentry (Fig top row). Models were successfully constructed from MRI (2nd row). The models were inducible for VTs with morphologies and cycle lengths (187±33 ms) that matched well with the experiment (3rd row). Simulations also revealed that in the cases of centrifugal activity, the underlying VT reentrant circuits were located intramurally within the ventricular wall where they were not detectable from surface recordings alone (Fig A 4th row).
Conclusions: These results demonstrate that MRI-based computer models of hearts with myocardial infarction provide a unique opportunity to predict and analyze VT resulting for from specific infarct zone architecture, and thus may assist clinicians in identifying and ablating the reentrant circuit(s).
Author Disclosures: D. Deng: None. H. Arevalo: None. H. Halperin: None. N. Trayanova: Ownership Interest; Modest; CardioSolv.
- © 2014 by American Heart Association, Inc.