Cardiac CT With Delayed Enhancement in the Characterization of Ventricular Tachycardia Structural Substrate. Relationship Between CT-Segmented Scar and Electro-Anatomic Mapping

Objectives: This study sought to compare myocardial scars depicted by computed tomography (CT) with electrical features from electro-anatomic mapping (EAM), assessing the potential role of CT integration in ventricular tachycardia (VT) and radiofrequency catheter ablation (RFCA) procedures. Background: Imaging-based characterization of VT myocardial substrate is required to plan EAM and, potentially, to guide RFCA. Methods: Forty-two consecutive patients, 35 of whom had implantable cardioverter-defibrillator, all referred for VT RFCA, underwent pre-procedural CT including an angiographic and a 10-min delayed-enhancement scan. Segmental comparison between scars segmented from CT and low voltages (bipolar voltages 2, bipolar voltages -EAM = 4,070 mm²; R = 0.78; p <0.0001). In this study, 70% and 84% of low-amplitude bipolar points were mapped at a maximum distance of 5 mm and 10 mm from CT-segmented scar, respectively. Conclusions: CT with delayed-enhancement provides a 3-dimensional characterization of VT scar substrate together with a detailed anatomic model of the heart. This information may offer assistance to plan EAM and RFCA procedures and is potentially suitable for EAM-imaging integration.