Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clinic, University of Barcelona, Barcelona, Spain.
Circ Arrhythm Electrophysiol. 2011 Oct;4(5):674-83. doi: 10.1161/CIRCEP.111.961946. Epub 2011 Aug 31.
Scar heterogeneity identified with contrast-enhanced cardiac magnetic resonance (CE-CMR) has been related to its arrhythmogenic potential by using different algorithms. The purpose of the study was to identify the algorithm that best fits with the electroanatomic voltage maps (EAM) to guide ventricular tachycardia (VT) ablation.
Three-dimensional scar reconstructions from preprocedural CE-CMR study at 3T were obtained and compared with EAMs of 10 ischemic patients submitted for a VT ablation. Three-dimensional scar reconstructions were created for the core (3D-CORE) and border zone (3D-BZ), applying cutoff values of 50%, 60%, and 70% of the maximum pixel signal intensity to discriminate between core and BZ. The left ventricular cavity from CE-CMR (3D-LV) was merged with the EAM, and the 3D-CORE and 3D-BZ were compared with the corresponding EAM areas defined with standard cutoff voltage values. The best match was obtained when a cutoff value of 60% of the maximum pixel signal intensity was used, both for core (r(2)=0.827; P<0.001) and BZ (r(2)=0.511; P=0.020), identifying 69% of conducting channels (CC) observed in the EAM. Matching improved when only the subendocardial half of the wall was segmented (CORE: r(2)=0.808; P<0.001 and BZ: r(2)=0.485; P=0.025), identifying 81% of CC. When comparing the location of each bipolar voltage intracardiac electrogram with respect to the 3D CE-CMR-derived structures, a Cohen κ coefficient of 0.70 was obtained.
Scar characterization by means of high resolution CE-CMR resembles that of EAM and can be integrated into the CARTO system to guide VT ablation.
利用不同算法，对比增强心脏磁共振（CE-CMR）识别的瘢痕异质性与心律失常潜能有关。本研究的目的是确定最适合与电解剖电压图（EAM）匹配的算法，以指导室性心动过速（VT）消融。
在 3T 行术前 CE-CMR 研究中获取三维瘢痕重建，并与 10 例缺血性患者进行的 VT 消融的 EAM 进行比较。应用 50%、60%和 70%最大像素信号强度的截断值，将三维瘢痕重建划分为核心区（3D-CORE）和边缘区（3D-BZ），以区分核心区和边缘区。将 CE-CMR 的左心室腔（3D-LV）与 EAM 融合，并将 3D-CORE 和 3D-BZ 与用标准电压截断值定义的相应 EAM 区域进行比较。当使用最大像素信号强度的 60%作为截断值时，核心区（r(2)=0.827；P<0.001）和边缘区（r(2)=0.511；P=0.020）均能获得最佳匹配，可识别 EAM 中观察到的 69%的传导通道（CC）。当仅对心内膜下壁的一半进行分段时，匹配效果会改善（CORE：r(2)=0.808；P<0.001 和 BZ：r(2)=0.485；P=0.025），可识别 81%的 CC。当比较每个双极电压心内电图相对于 3D CE-CMR 衍生结构的位置时，得到 Cohen κ 系数为 0.70。
通过高分辨率 CE-CMR 对瘢痕进行特征描述类似于 EAM，可整合到 CARTO 系统中，以指导 VT 消融。
