Improving safety of epicardial ventricular tachycardia ablation using the scar dechanneling technique and the integration of anatomy, scar components, and coronary arteries into the navigation system.

A 54-year-old patient with a nonischemic cardiomyopathy, mild left ventricular dysfunction, and a nonsyncopal ventricular tachycardia was admitted for an ablation procedure. Preprocedural contrast-enhanced cardiac magnetic resonance (ce-CMR) was performed with a 3T clinical scanner (Magnetom Trio, Siemens Healthcare, Erlangen, Germany). A free-breathing 3-dimensional navigator and electrocardiographically gated inversion-recovery gradient-echo sequence was applied in the axial orientation, starting 5 minutes after an intravenous injection of 0.2 mmol/kg gadodiamide. Image acquisition parameters were set to allow a true isotropic 1.2×1.2×1.2-mm spatial resolution, and the acquisition time was targeted below 9 minutes to permit simultaneous evaluation of the coronary tree and myocardial enhancement. To minimize motion artifacts, the acquisition window was selected with a high-temporal-resolution 4-chamber cine view. The patient was instructed to maintain shallow and steady breathing during the acquisition. The full volume was reconstructed in the left ventricular short-axis orientation, and the resulting images were processed with self-customized software (TCTK [Tissue Characterization Tool Kit], Barcelona, Spain). An algorithm based on the pixel signal intensity was applied to characterize the hyperenhanced area as scar core or border zone. The processed images were imported into the CARTO system (Biosense Webster, Diamond Bar, CA). The study showed …