Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.
Cardiac Electrophysiology Section, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA.
JACC Clin Electrophysiol. 2020 Oct 26;6(11):1452-1464. doi: 10.1016/j.jacep.2020.08.033.
This study sought to investigate the sensitivity of electroanatomical mapping (EAM) to detect scar as identified by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR).
Previous studies have shown correlation between low voltage electrogram amplitude and myocardial scar. However, voltage amplitude is influenced by the distance between the scar and the mapping surface and its extent. The aim of this study is to examine the reliability of low voltage EAM as a surrogate for myocardial scar using LGE-derived scar as the reference.
Twelve swine underwent anterior wall infarction by occlusion of the left anterior descending artery (LAD) (n = 6) or inferior wall infarction by occlusion of the left circumflex artery (LCx) (n = 6). Subsequently, animals underwent CMR and EAM using a multielectrode mapping catheter. CMR characteristics, including wall thickness, LGE location and extent, and EAM maps, were independently analyzed, and concordance between voltage maps and CMR characteristics was assessed.
LGE volume was similar between the LCx and LAD groups (8.5 ± 2.2 ml vs. 8.3 ± 2.5 ml, respectively; p = 0.852). LGE scarring in the LAD group was more subendocardial, affected a larger surface area, and resulted in significant wall thinning (4.88 ± 0.43 mm). LGE scarring in the LCx group extended from the endocardium to the epicardium with minimal reduction in wall thickness (scarred: 5.4 ± 0.67 mm vs. remote: 6.75 ± 0.38 mm). In all the animals in the LAD group, areas of low voltage corresponded with LGE and wall thinning, whereas only 2 of 6 animals in the LCx group had low voltage areas on EAM. Bipolar and unipolar voltage amplitudes were higher in thick inferior walls in the LCx group than in thin anterior walls in the LAD group, despite a similar LGE volume.
Discordances between LGE-detected scar areas and low voltage areas by EAM highlighted the limitations of the current EAM system to detect scar in thick myocardial wall regions.
本研究旨在探讨心脏磁共振（CMR）晚期钆增强（LGE）检测到的瘢痕组织的电解剖图（EAM）的敏感性。
先前的研究表明，低电压电描记图幅度与心肌瘢痕之间存在相关性。然而，电压幅度受到瘢痕与映射表面之间的距离及其程度的影响。本研究旨在使用 LGE 衍生的瘢痕作为参考，检查低电压 EAM 作为心肌瘢痕替代物的可靠性。
12 头猪通过阻塞左前降支（LAD）（n=6）或左回旋支（LCx）（n=6）导致前壁或下壁梗死。随后，动物接受 CMR 和使用多电极映射导管进行 EAM。独立分析 CMR 特征，包括壁厚度、LGE 位置和范围以及 EAM 图谱，并评估电压图谱与 CMR 特征之间的一致性。
LCx 和 LAD 组的 LGE 体积相似（分别为 8.5±2.2ml 和 8.3±2.5ml；p=0.852）。LAD 组的 LGE 瘢痕更接近心内膜，影响的表面积更大，导致壁明显变薄（4.88±0.43mm）。LCx 组的 LGE 瘢痕从心内膜延伸到心外膜，壁厚度减少最小（瘢痕区：5.4±0.67mm 比远侧区：6.75±0.38mm）。在 LAD 组的所有动物中，低电压区域与 LGE 和壁变薄相对应，而在 LCx 组的 6 只动物中只有 2 只在 EAM 上有低电压区域。尽管 LGE 体积相似，但 LCx 组厚下壁的双极和单极电压幅度高于 LAD 组薄前壁。
LGE 检测到的瘢痕区域与 EAM 检测到的低电压区域之间的不一致性突出了当前 EAM 系统在检测厚心肌壁区域瘢痕组织方面的局限性。
