Cardiovascular Medicine Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
JACC Clin Electrophysiol. 2018 Mar;4(3):291-303. doi: 10.1016/j.jacep.2017.09.175. Epub 2017 Nov 29.
This study sought to characterize the electroanatomic (EAM) substrate in patients with cardiac sarcoidosis (CS) and ventricular tachycardia and its relationship to imaging findings of inflammation and fibrosis.
CS is characterized by coexistence of active inflammation and replacement fibrosis.
A total of 42 patients with CS based on established criteria and ventricular tachycardia underwent high-density EAM mapping. Abnormal electrograms (EGM) were collected and independently classified as multicomponent fractionated, isolated, late, and split according to standard criteria and regardless of the peak-to-peak bipolar/unipolar voltage. A total of 29 patients (69%) underwent pre-procedural cardiac magnetic resonance (CMR) and positron emission tomography (PET)/computed tomography (CT). The distribution of EAM substrate was correlated with regions of late gadolinium enhancement (LGE) on CMR and increased 18F-fluorodeoxyglucose uptake on PET/CT.
Of 21,451 bipolar and unipolar EGM, 4,073 (19%) were classified as abnormal with a predominant distribution in the basal perivalvular segments and interventricular septum. Using the standard bipolar (<1.5 mV) and unipolar (<8.3 mV for left ventricle <5.5 mV for the right) voltage cutoff values, 40% and 22% of the abnormal EGM were located outside the EAM low-voltage areas, respectively. LGE was present in 26 of 29 patients (90%), whereas abnormal 18F-fluorodeoxyglucose uptake in 14 of 29 patients (48%) with imaging. Segments with abnormal EGM had more LGE-evident scar transmurality [median: 24% (interquartile range [IQR]: 4% to 40%) vs. median: 5% (IQR: 0% to 15%); p < 0.001] and lower metabolic activity (median: 20 g glucose [IQR: 14 g to 30 g] vs. median: 29 g glucose [IQR: 18 g to 39 g]; p < 0.001). Overall, the agreement between the presence of abnormal EGM was higher with the presence of LGE (κ = 0.51; p < 0.001) than with the presence of active inflammation (κ = -0.12; p = 0.003).
In patients with CS and ventricular tachycardia, pre-procedural imaging with CMR and PET/CT can be useful in detecting EAM abnormalities that are potential targets for substrate ablation. Abnormal EGM were more likely located in segments with more scar transmurality (LGE) at CMR and a lower degree of inflammation on PET.
本研究旨在描述心肌结节病（CS）伴室性心动过速患者的电解剖（EAM）基质及其与炎症和纤维化影像学表现的关系。
CS 的特征是同时存在活跃的炎症和替代纤维化。
根据既定标准和室性心动过速，共纳入 42 例 CS 患者进行高密度 EAM 标测。收集异常电图（EGM），并根据标准标准独立分类为多成分碎裂、孤立、晚期和分裂，而不考虑峰峰值双极/单极电压。共有 29 例（69%）患者在术前进行心脏磁共振（CMR）和正电子发射断层扫描（PET）/计算机断层扫描（CT）检查。EAM 基质的分布与 CMR 上晚期钆增强（LGE）和 PET/CT 上 18F-氟脱氧葡萄糖摄取增加的区域相关。
在 21451 个双极和单极 EGM 中，4073 个（19%）被归类为异常，主要分布在基底部瓣周段和室间隔。使用标准的双极（<1.5 mV）和单极（左心室<8.3 mV，右心室<5.5 mV）电压截断值，分别有 40%和 22%的异常 EGM 位于 EAM 低电压区域之外。29 例患者中有 26 例（90%）存在 LGE，29 例患者中有 14 例（48%）存在异常 18F-氟脱氧葡萄糖摄取。存在异常 EGM 的节段 LGE 明显瘢痕透壁性更高[中位数：24%（四分位距[IQR]：4%40%）vs.中位数：5%（IQR：0%15%）；p<0.001]，代谢活性更低（中位数：20 g 葡萄糖[IQR：14 g30 g]vs.中位数：29 g 葡萄糖[IQR：18 g39 g]；p<0.001）。总体而言，异常 EGM 的存在与 LGE 的存在具有更高的一致性（κ=0.51；p<0.001），而与活性炎症的存在一致性较差（κ=-0.12；p=0.003）。
在 CS 伴室性心动过速患者中，术前 CMR 和 PET/CT 成像有助于检测 EAM 异常，这些异常可能是基质消融的潜在靶点。异常 EGM 更可能位于 CMR 上瘢痕透壁性更高（LGE）的节段和 PET 上炎症程度更低的节段。
