Nakamura Toshihiro, Kiuchi Kunihiko, Fukuzawa Koji, Takami Mitsuru, Watanabe Yoshiaki, Izawa Yu, Takemoto Makoto, Sakai Jun, Yatomi Atsusuke, Sonoda Yusuke, Takahara Hiroyuki, Nakasone Kazutaka, Yamamoto Kyoko, Suzuki Yuya, Tani Ken-Ichi, Negi Noriyuki, Kono Atsushi, Ashihara Takashi, Hirata Ken-Ichi
Section of Arrhythmia Division of Cardiovascular Medicine Department of Internal Medicine Kobe University Graduate School of Medicine Kobe Japan.
Department of Radiology Kobe University Graduate School of Medicine Kobe Japan.
J Arrhythm. 2022 Jan 13;38(2):221-231. doi: 10.1002/joa3.12676. eCollection 2022 Apr.
Some of atrial fibrillation (AF) drivers are found in normal/mild late-gadolinium enhancement (LGE) areas, as well as moderate ones. The atrial wall thickness (AWT) has been reported to be important as a possible AF substrate. However, the AWT and degree of LGEs as an AF substrate has not been fully validated in humans.
The purpose of this study was to evaluate the impact of the AWT in normal/mild LGE areas on AF drivers.
A total of 287 segments in 15 persistent AF patients were assessed. AF drivers were defined as non-passively activated areas (NPAs), where rotational activation was frequently observed, and were detected by the novel real-time phase mapping (ExTRa Mapping), mild LGE areas were defined as areas with a volume ratio of the enhancement voxel of 0% to <10%. The AWT was defined as the minimum distance from the manually determined endocardium to the epicardial border on the LGE-MRI.
NPAs were found in 20 (18.0%) of 131 normal/mild LGE areas where AWT was significantly thicker than that in the passively activated areas (PAs) (2.5 ± 0.3 vs. 2.2 ± 0.3 mm, < .001). However, NPAs were found in 41 (26.3%) of 156 moderate LGE areas where AWT was thinner than that of PAs (2.1 ± 0.2 mm vs. 2.23 ± 0.3 mm, = .02). An ROC curve analysis yielded an optimal cutoff value of 2.2 mm for predicting the presence of an NPA in normal/mild LGE areas.
The location of AF drivers in normal/mild LGE areas might be more accurately identified by evaluating AWT.
心房颤动（AF）的一些驱动因素存在于正常/轻度延迟钆增强（LGE）区域以及中度LGE区域。据报道，心房壁厚度（AWT）作为一种可能的AF基质很重要。然而，AWT和LGE程度作为AF基质在人类中尚未得到充分验证。
本研究的目的是评估正常/轻度LGE区域中AWT对AF驱动因素的影响。
对15例持续性AF患者的287个节段进行了评估。AF驱动因素被定义为非被动激活区域（NPA），在该区域经常观察到旋转激活，并通过新型实时相位映射（ExTRa Mapping）检测到，轻度LGE区域被定义为增强体素体积比为0%至<10%的区域。AWT被定义为在LGE-MRI上从手动确定的心内膜到心外膜边界的最小距离。
在131个正常/轻度LGE区域中的20个（18.0%）发现了NPA，这些区域的AWT明显厚于被动激活区域（PA）（2.5±0.3 vs. 2.2±0.3mm，<0.001）。然而，在156个中度LGE区域中的41个（26.3%）发现了NPA，这些区域的AWT比PA薄（2.1±0.2mm vs. 2.23±0.3mm，=0.02）。ROC曲线分析得出预测正常/轻度LGE区域中NPA存在的最佳截断值为2.2mm。
通过评估AWT可能更准确地识别正常/轻度LGE区域中AF驱动因素的位置。
