Dharmaprani Dhani, McGavigan Andrew D, Chapman Darius, Kutlieh Rayed, Thanigaimani Shivshankar, Dykes Lukah, Kalman Jonathan, Sanders Prashanthan, Pope Kenneth, Kuklik Pawel, Ganesan Anand N
College of Medicine and Public Health, Flinders University of South Australia, Adelaide, SA, Australia.
College of Medicine and Public Health, Flinders University of South Australia, Adelaide, SA, Australia; Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia.
J Electrocardiol. 2019 Mar-Apr;53:18-27. doi: 10.1016/j.jelectrocard.2018.11.014. Epub 2018 Nov 20.
The potential utility of entropy (En) for atrial fibrillation (AF) mapping has been demonstrated in previous studies by multiple groups, where an association between high bipolar electrogram (EGM) entropy and the pivot of rotors has been shown. Though En is potentially attractive new approach to ablation, no studies have examined its temporal stability and specificity, which are critical to the application of entropy to clinical ablation. In the current study, we sought to objectively measure the temporal stability and specificity of bipolar EGM entropy in medium to long term recordings using three studies: i) a human basket catheter AF study, ii) a tachypaced sheep AF study and iii) a computer simulation study.
To characterize the temporal dynamics and specificity of Approximate, Sample and Shannon entropy (ApEn/SampEn/ShEn) in human (H), sheep (S), and computer simulated AF.
64-electrode basket bi-atria sustained AF recordings (H:15 min; S:40 min) were separated into 5 s segments. ShEn/ApEn/SampEn were computed, and co-registered with NavX 3D maps. Temporal stability was determined in terms of: (i) global pattern stability of En and (ii) the relative stability the top 10% of En regions. To provide mechanistic insights into underlying mechanisms, stability characteristics were compared to models depicting various propagation patterns. To verify these results, cross-validation was performed across multiple En algorithms, across species, and compared with dominant frequency (DF) temporal characteristics. The specificity of En was also determined by looking at the association of En to rotors and areas of wave cross propagation.
Episodes of AF were analysed (H:26 epochs, 6040 s; S:15 epochs, 14,160 s). The global pattern of En was temporally unstable (CV- H:13.42% ± 4.58%; S:14.13% ± 8.13%; Friedman- H: p > 0.001; S: p > 0.001). However, within this dynamic flux, the top 10% of ApEn/SampEn/ShEn regions were relatively temporally stable (Kappa >0.6) whilst the top 10% of DF regions were unstable (Kappa <0.06). In simulated AF scenarios, the experimental data were optimally reproduced in the context of an AF pattern with stable rotating waves surrounded by wavelet breakup (Kappa: 0.610; p < 0.0001).
En shows global temporal instability, however within this dynamic flux, the top 10% regions exhibited relative temporal stability. This suggests that high En regions may be an appealing ablation target. Despite this, high En was associated with not just the pivot of rotors but also with areas of cross propagation, which suggests the need for future work before clinical application is possible.
多个研究小组在之前的研究中已证明熵（En）在心房颤动（AF）标测中的潜在效用，其中已显示高双极电图（EGM）熵与转子中心之间存在关联。尽管En是一种潜在有吸引力的新消融方法，但尚无研究考察其时间稳定性和特异性，而这对于熵在临床消融中的应用至关重要。在本研究中，我们试图通过三项研究客观测量中长期记录中双极EGM熵的时间稳定性和特异性：i）一项人体篮状导管房颤研究，ii）一项快速起搏绵羊房颤研究，以及iii）一项计算机模拟研究。
描述人体（H）、绵羊（S）和计算机模拟房颤中近似熵、样本熵和香农熵（ApEn/SampEn/ShEn）的时间动态和特异性。
将64电极篮状双心房持续性房颤记录（H：15分钟；S：40分钟）分成5秒的片段。计算ShEn/ApEn/SampEn，并与NavX 3D地图共同配准。根据以下方面确定时间稳定性：（i）En的全局模式稳定性，以及（ii）En区域中前10%的相对稳定性。为了深入了解潜在机制，将稳定性特征与描述各种传播模式的模型进行比较。为了验证这些结果，在多种En算法、不同物种间进行交叉验证，并与主导频率（DF）的时间特征进行比较。En的特异性还通过观察En与转子以及波交叉传播区域的关联来确定。
分析了房颤发作情况（H：26个时段，6040秒；S：15个时段，14160秒）。En的全局模式在时间上不稳定（CV - H：13.42%±4.58%；S：14.13%±8.13%；Friedman - H：p>0.001；S：p>0.001）。然而，在这种动态变化中，ApEn/SampEn/ShEn区域中前10%在时间上相对稳定（Kappa>0.6），而DF区域中前10%则不稳定（Kappa<0.06）。在模拟房颤场景中，在具有稳定旋转波且周围有小波破碎的房颤模式下，实验数据得到了最佳重现（Kappa：0.610；p<0.0001）。
En显示出全局时间不稳定性，然而在这种动态变化中，前10%的区域表现出相对时间稳定性。这表明高En区域可能是一个有吸引力的消融靶点。尽管如此，高En不仅与转子中心相关，还与交叉传播区域相关，这表明在临床应用之前还需要进一步的研究。
