Akutsu Yasushi, Tanno Kaoru, Kobayashi Youichi
Division of Cardiology, Department of Medicine Showa University School of Medicine, Tokyo, Japan.
J Atr Fibrillation. 2012 Aug 20;5(2):509. doi: 10.4022/jafib.509. eCollection 2012 Aug-Sep.
Atrial fibrillation (AF) is the most common arrhythmia and is associated with a significant morbidity and mortality. Invasive catheter ablation of AF has emerged as an effective therapy for patients with symptomatic AF. Atrial remodeling, particularly structural remodeling, is important not only for AF persistence but also for AF recurrence after ablation. Atrial dilation and fibrosis are two of the core processes involved in atrial structural remodeling. Increased automaticity and triggered activity occur in atrial structural remodeling, which may cause difficulty in maintaining sinus rhythm after ablation. Furthermore, an enlarged left atrium (LA) may increase the difficulty in achieving catheter stability and thereby require more energy to complete AF ablation. AF causes similar remodeling in both the left and right atria (RA), and myocardial changes in both atria influence AF recurrence. A non-invasive assessment of fibrotic structural remodeling helps predict the outcome of AF ablation. A varie ty of cardiac imaging modalities, such as two- or three-dimensional echocardiography or multi-detector row computed tomography, have been used to estimate the magnitude of atrial structural remodeling by measuring atrial volume or LA function. Furthermore, delayed enhanced cardiac magnetic resonance imaging has been used to detect not only atrial fibrosis but also the effect of the ablation point. Thus, atrial remodeling, particularly structural remodeling, plays an important role in AF recurrence. These non-invasive imaging modalities are significant tools for estimating atrial enlargement to improve patient selection for AF ablation at the point of paroxysmal AF, and for estimating atrial fibrosis to select the AF treatment including ablation strategy at the point of development to persistent or permanent AF.
心房颤动（AF）是最常见的心律失常，与显著的发病率和死亡率相关。房颤的侵入性导管消融已成为有症状房颤患者的有效治疗方法。心房重构，尤其是结构重构，不仅对房颤的持续存在很重要，而且对消融术后房颤的复发也很重要。心房扩张和纤维化是心房结构重构所涉及的两个核心过程。心房结构重构中会出现自律性增加和触发活动，这可能导致消融术后维持窦性心律困难。此外，左心房（LA）增大可能会增加实现导管稳定性的难度，从而需要更多能量来完成房颤消融。房颤会在左心房和右心房（RA）引起类似的重构，两个心房的心肌变化都会影响房颤复发。纤维化结构重构的非侵入性评估有助于预测房颤消融的结果。多种心脏成像方式，如二维或三维超声心动图或多排探测器计算机断层扫描，已被用于通过测量心房容积或左心房功能来估计心房结构重构的程度。此外，延迟增强心脏磁共振成像不仅已被用于检测心房纤维化，还可检测消融点的效果。因此，心房重构，尤其是结构重构，在房颤复发中起重要作用。这些非侵入性成像方式是重要工具，可用于在阵发性房颤阶段估计心房扩大以改善房颤消融的患者选择，以及在房颤发展为持续性或永久性房颤阶段估计心房纤维化以选择包括消融策略在内的房颤治疗方法。
