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

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• 作者：Antonio Esposito ; MD^a ; ^b ; ^{esposito.antonio@hsr.it" class="auth_mail" title="E-mail the corresponding author} ; Anna Palmisano ; MD^a ; ^b ; Sofia Antunes ; PhD^c ; Giuseppe Maccabelli ; MD^d ; Caterina Colantoni ; MD^a ; ^b ; Paola Maria Vittoria Rancoita ; PhD^e ; Francesca Baratto ; MD^d ; Clelia Di Serio ; PhD^e ; Giovanna Rizzo ; MSc^f ; Francesco De Cobelli ; MD^a ; ^b ; Paolo Della Bella ; MD^d ; Alessandro Del Maschio ; MD^a ; ^b
• 关键词：cardiac computed tomography ; computed tomography delayed enhancement ; electro-anatomic mapping ; radiofrequency catheter ablation ; ventricular tachycardia
• 刊名：JACC: Cardiovascular Imaging
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：9
• 期：7
• 页码：822-832
• 全文大小：1738 K

文摘

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 <1.5 mV; unipolar voltages <8 mV), late potentials, and RF ablation points on EAM, was carried out. In a subset of 16 consecutive patients, a further point-by-point analysis was performed: a CT-derived 3-dimensional structure including heart anatomy and myocardial scars was integrated with EAM for quantitative comparison.

Results

CT scans identified scars in 39 patients and defined left ventricular wall involvement and mural distribution. Overall segmental concordance between CT and EAM was good (κ = 0.536) despite the presence of implantable cardioverter-defibrillator, scar etiologies, and mural distribution. CT identified segments characterized by low voltages with good sensitivity (76%), good specificity (86%), and very high negative predictive value (95%). Late potentials and RF ablation points fell on scarred segments identified from CT in 79% and 81% of cases, respectively. Point-by-point quantitative comparison revealed good correlation between the average area of scar detected at CT and at bipolar mapping (CT = 4,901 mm², 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.