New insight into scar-related ventricular tachycardia circuits in ischemic cardiomyopathy: Fat deposition after myocardial infarction on computed tomography-A pilot study
New insight into scar-related ventricular tachycardia circuits in ischemic cardiomyopathy: Fat deposition after myocardial infarction on computed tomography-A pilot study
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DOI：
10.1016/j.hrthm.2015.03.041
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发表时间：
2015-07-01
期刊：
影响因子：
5.5
通讯作者：
Zimmerman, Stefan L.
中科院分区：
文献类型：
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作者：
Sasaki, Takeshi;Calkins, Hugh;Zimmerman, Stefan L.
背景心肌脂肪沉积（FAT-DEP）经常出现在缺血性心肌病患者的慢性心肌梗死区域。瘢痕相关的室性心动过速（VT）circuits. ObjectiveThis试点研究的目的是评估心肌脂肪-DEP局部心电图和VT电路缺血性cardiomyopathy.METHODS对比增强计算机断层扫描的影响在22例缺血性VT。将电解剖标测图点与相应的对比增强计算机断层扫描图像配准。使用后处理图像叠加（突出显示低于0 Hounsfield单位（HU）的区域）识别和表征心肌FAT-DEP。在短轴图像上测量与采样电描记图相对应的局部心肌区域的平均衰减。结果1801个电解剖标测点中，519个（28.8%）位于FAT-DEP区域。在平均强度方面观察到显著差异（23.2 ± 35.6 HU vs 81.7 ± 21.9 HU; P < .001），双相（0.75 +/- 0.83 mV vs 2.9 +/- 2.4 mV; P < .001）和单极（3.1 +/- 1.7 mV vs 7.4 +/- 4.3 mV; P < .001）有和没有FAT-DEP的区域之间的振幅和左心室壁厚度（5.2 +/- 1.7 mm vs 8.2 +/- 2.5 mm; P < .001）。低HU与低双极和单极振幅密切相关（分别为P <0.0001）。结论FAT-DEP与心电图特征及VT发生部位有关。需要进一步的工作来确定FAT-DEP是否在缺血性瘢痕相关VT回路的产生中起因果作用。
BACKGROUND Myocardial fat deposition (FAT-DEP) has been frequently observed in regions of chronic myocardial infarction in patients with ischemic cardiomyopathy. The role of FAT-DEP within scar-related ventricular tachycardia (VT) circuits has not been investigated.OBJECTIVE This pilot study aimed to assess the impact of myocardial FAT-DEP on local electrograms and VT circuits in patients with ischemic cardiomyopathy.METHODS Contrast-enhanced computed tomography was performed in 22 patients with ischemic VT. Electroanatomic map points were registered to the corresponding contrast-enhanced computed tomography images. Myocardial FAT-DEP was identified and characterized using a postprocessing image overlay that highlighted areas below 0 Hounsfield units (HU). The mean attenuation of local myocardial regions corresponding to sampled electrograms was measured on short-axis images. The associations of mean attenuation with bipolar and unipolar amplitudes, left ventricular wall thickness, and VT circuit sites were investigated.RESULTS Of 1801 electroanatomic map points, 519 (28.8%) were located in regions with FAT-DEP. Significant differences were observed in mean intensity (23.2 +/- 35.6 HU vs 81.7 +/- 21.9 HU; P < .001), bipolar (0.75 +/- 0.83 mV vs 2.9 +/- 2.4 mV; P < .001) and unipolar (3.1 +/- 1.7 mV vs 7.4 +/- 4.3 mV; P < .001) amplitudes, and left ventricular wall thickness (5.2 +/- 1.7 mm vs 8.2 +/- 2.5 mm; P < .001) between regions with and without FAT-DEP. Lower HU was strongly associated with lower bipolar and unipolar amplitudes (P < .0001, respectively). Importantly, FAT-DEP was associated with critical VT circuit sites with fractionated or isolated potentials.CONCLUSION FAT-DEP was associated with electrogram characteristics and VT circuit sites. Further work will be needed to determine whether FAT-DEP plays a causal role in the generation of ischemic scar-related VT circuits.