Tao Susumu, Way Samuel F, Garland Joshua, Chrispin Jonathan, Ciuffo Luisa A, Balouch Muhammad A, Nazarian Saman, Spragg David D, Marine Joseph E, Berger Ronald D, Calkins Hugh, Ashikaga Hiroshi
Cardiac Arrhythmia Service, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
Department of Computer Science, University of Colorado, Boulder, Colorado, United States of America.
PLoS One. 2017 Jul 5;12(7):e0179459. doi: 10.1371/journal.pone.0179459. eCollection 2017.
Persistent atrial fibrillation (AF) can be viewed as disintegrated patterns of information transmission by action potential across the communication network consisting of nodes linked by functional connectivity. To test the hypothesis that ablation of persistent AF is associated with improvement in both local and global connectivity within the communication networks, we analyzed multi-electrode basket catheter electrograms of 22 consecutive patients (63.5 ± 9.7 years, 78% male) during persistent AF before and after the focal impulse and rotor modulation-guided ablation. Eight patients (36%) developed recurrence within 6 months after ablation. We defined communication networks of AF by nodes (cardiac tissue adjacent to each electrode) and edges (mutual information between pairs of nodes). To evaluate patient-specific parameters of communication, thresholds of mutual information were applied to preserve 10% to 30% of the strongest edges. There was no significant difference in network parameters between both atria at baseline. Ablation effectively rewired the communication network of persistent AF to improve the overall connectivity. In addition, successful ablation improved local connectivity by increasing the average clustering coefficient, and also improved global connectivity by decreasing the characteristic path length. As a result, successful ablation improved the efficiency and robustness of the communication network by increasing the small-world index. These changes were not observed in patients with AF recurrence. Furthermore, a significant increase in the small-world index after ablation was associated with synchronization of the rhythm by acute AF termination. In conclusion, successful ablation rewires communication networks during persistent AF, making it more robust, efficient, and easier to synchronize. Quantitative analysis of communication networks provides not only a mechanistic insight that AF may be sustained by spatially localized sources and global connectivity, but also patient-specific metrics that could serve as a valid endpoint for therapeutic interventions.
持续性心房颤动（AF）可被视为动作电位在由功能连接相连的节点组成的通信网络中传递信息的瓦解模式。为了验证持续性AF消融与通信网络内局部和全局连接性改善相关的假设，我们分析了22例连续患者（63.5±9.7岁，78%为男性）在局灶性冲动和转子调制引导消融前后持续性AF期间的多电极篮状导管心电图。8例患者（36%）在消融后6个月内复发。我们通过节点（每个电极相邻的心脏组织）和边（节点对之间的互信息）定义AF的通信网络。为了评估特定患者的通信参数，应用互信息阈值来保留10%至30%最强的边。基线时两心房之间的网络参数无显著差异。消融有效地重新连接了持续性AF的通信网络，以改善整体连接性。此外，成功的消融通过增加平均聚类系数改善了局部连接性，并且通过缩短特征路径长度改善了全局连接性。结果，成功的消融通过增加小世界指数提高了通信网络的效率和鲁棒性。在AF复发的患者中未观察到这些变化。此外，消融后小世界指数的显著增加与急性AF终止导致的节律同步相关。总之，成功的消融在持续性AF期间重新连接通信网络，使其更加强健、高效且易于同步。通信网络的定量分析不仅提供了一种机制性见解，即AF可能由空间局部化源和全局连接性维持，还提供了特定患者的指标，这些指标可作为治疗干预的有效终点。
