Department of Computer Applications in Science and Engineering, Barcelona Supercomputing Center (BSC), Jordi Girona, 29, Barcelona, Spain.
Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Myocardial Pathophysiology Area, Melchor Fernández Almagro, 2, Madrid, Spain.
Europace. 2019 Jan 1;21(1):163-174. doi: 10.1093/europace/euy192.
We aimed to study the differences in biventricular scar characterization using bipolar voltage mapping compared with state-of-the-art in vivo delayed gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) imaging and ex vivo T1 mapping.
Ten pigs with established myocardial infarction (MI) underwent in vivo scar characterization using LGE-CMR imaging and high-density voltage mapping of both ventricles using a 3.5-mm tip catheter. Ex vivo post-contrast T1 mapping provided a high-resolution reference. Voltage maps were registered onto the left and right ventricular (LV and RV) endocardium, and epicardium of CMR-based geometries to compare voltage-derived scars with surface-projected 3D scars. Voltage-derived scar tissue of the LV endocardium and the epicardium resembled surface projections of 3D in vivo and ex vivo CMR-derived scars using 1-mm of surface projection distance. The thinner wall of the RV was especially sensitive to lower resolution in vivo LGE-CMR images, in which differences between normalized low bipolar voltage areas and CMR-derived scar areas did not decrease below a median of 8.84% [interquartile range (IQR) (3.58, 12.70%)]. Overall, voltage-derived scars and surface scar projections from in vivo LGE-CMR sequences showed larger normalized scar areas than high-resolution ex vivo images [12.87% (4.59, 27.15%), 18.51% (11.25, 24.61%), and 9.30% (3.84, 19.59%), respectively], despite having used optimized surface projection distances. Importantly, 43.02% (36.54, 48.72%) of voltage-derived scar areas from the LV endocardium were classified as non-enhanced healthy myocardium using ex vivo CMR imaging.
In vivo LGE-CMR sequences and high-density voltage mapping using a conventional linear catheter fail to provide accurate characterization of post-MI scar, limiting the specificity of voltage-based strategies and imaging-guided procedures.
本研究旨在比较双极电压标测与最新的体内钆延迟增强心脏磁共振（LGE-CMR）成像和离体 T1 映射，研究双心室瘢痕特征的差异。
10 头已建立心肌梗死（MI）模型的猪接受了 LGE-CMR 成像的体内瘢痕特征研究，并使用 3.5mm 尖端导管对双心室进行高密度电压标测。离体对比后 T1 映射提供了高分辨率参考。将电压图注册到基于 CMR 的左心室（LV）和右心室（RV）心内膜和心外膜上，以比较电压衍生瘢痕与表面投影 3D 瘢痕。LV 心内膜和心外膜的电压衍生瘢痕组织类似于表面投影 3D 体内和离体 CMR 衍生瘢痕，使用 1mm 的表面投影距离。RV 较薄的壁对体内 LGE-CMR 图像的较低分辨率特别敏感，其中归一化低双极电压区域与 CMR 衍生瘢痕区域之间的差异未降至中位数 8.84%[四分位距（IQR）（3.58，12.70%）]以下。总体而言，电压衍生瘢痕和来自体内 LGE-CMR 序列的表面瘢痕投影显示出比高分辨率离体图像更大的归一化瘢痕面积[分别为 12.87%（4.59，27.15%）、18.51%（11.25，24.61%）和 9.30%（3.84，19.59%）]，尽管使用了优化的表面投影距离。重要的是，LV 心内膜的电压衍生瘢痕面积有 43.02%（36.54，48.72%）被归类为离体 CMR 成像的非增强健康心肌。
体内 LGE-CMR 序列和使用常规线性导管的高密度电压标测无法提供 MI 后瘢痕的准确特征，限制了基于电压的策略和成像引导程序的特异性。
