Institute of Cardiometabolism and Nutrition, Paris, France.
Cardiovasc Res. 2014 May 1;102(2):205-13. doi: 10.1093/cvr/cvu045. Epub 2014 Mar 18.
Atrial fibrillation (AF) is the most frequent cardiac arrhythmia in clinical practice. AF is often associated with profound functional and structural alterations of the atrial myocardium that compose its substrate. Recently, a relationship between the thickness of epicardial adipose tissue (EAT) and the incidence and severity of AF has been reported. Adipose tissue is a biologically active organ regulating the metabolism of neighbouring organs. It is also a major source of cytokines. In the heart, EAT is contiguous with the myocardium without fascia boundaries resulting in paracrine effects through the release of adipokines. Indeed, Activin A, which is produced in abundance by EAT during heart failure or diabetes, shows a marked fibrotic effect on the atrial myocardium. The infiltration of adipocytes into the atrial myocardium could also disorganize the depolarization wave front favouring micro re-entry circuits and local conduction block. Finally, EAT contains progenitor cells in abundance and therefore could be a source of myofibroblasts producing extracellular matrix. The study on the role played by adipose tissue in the pathogenesis of AF is just starting and is highly likely to uncover new biomarkers and therapeutic targets for AF.
心房颤动（AF）是临床实践中最常见的心律失常。AF 通常与构成其基质的心房心肌的深刻功能和结构改变有关。最近，有人报告了心外膜脂肪组织（EAT）的厚度与 AF 的发生率和严重程度之间存在关系。脂肪组织是调节邻近器官代谢的具有生物活性的器官。它也是细胞因子的主要来源。在心内，EAT 与心肌没有筋膜边界相邻，通过释放脂肪因子产生旁分泌作用。事实上，在心力衰竭或糖尿病期间，EAT 大量产生的激活素 A 对心房心肌表现出明显的纤维化作用。脂肪细胞浸润到心房心肌也可能使去极化波阵面混乱，有利于微折返环和局部传导阻滞。最后，EAT 富含祖细胞，因此可能是产生细胞外基质的成纤维细胞的来源。关于脂肪组织在 AF 发病机制中所起作用的研究才刚刚开始，很可能会为 AF 发现新的生物标志物和治疗靶点。
