Department of Anatomy, Postgraduate Institute of Medical Education and Research, Sector-12, Chandigarh, 160012, India.
Surg Radiol Anat. 2022 Jan;44(1):129-136. doi: 10.1007/s00276-021-02864-w. Epub 2022 Jan 7.
The atrial muscle sleeve (AMS) of the pulmonary vein is the most common source of the arrhythmogenic triggers in atrial fibrillation (AF). Anatomical substrate generating these ectopic currents is still elusive. The present study was designed to study the AMS of pulmonary veins with an emphasis on the structural basis which might govern AF initiation and perpetuation.
The study was conducted on a longitudinal tissue section of pulmonary vein, taken from 15 human cadaveric nondiseased hearts. Tissue was studied histologically using H&E and Gömöri trichrome stain. The pacemaker channels were identified by immunohistochemistry using monoclonal HCN4 and HCN1 antibodies.
The AMS was identified in each pulmonary vein, located between the tunica adventitia and tunica media. A node-like arrangement of myocytes was seen within the AMS in 30% of veins. It had a compact zone limited by a fibrous capsule and contained much smaller, paler and interconnected myocytes. Outside the capsule, there was a zone of dispersed, singly placed myocytes separating the compact zone from the working myocytes of the AMS. HCN4 and HCN1 antibodies were expressed on the cell membrane of nodal myocytes, while the working myocytes demonstrated none to minimal staining.
Pulmonary veins nodes are similar to the specialized cardiac conductive tissue in the histological arrangement of compact and transitional zones, cellular characteristics and the presence of pacemaker channels. They might be the anatomical basis of ectopic arrhythmogenic foci. To our knowledge, these nodes are being described for the first time in human.
肺静脉的心房肌袖（AMS）是心房颤动（AF）中致心律失常触发灶的最常见来源。产生这些异位电流的解剖学基质仍难以捉摸。本研究旨在研究肺静脉的 AMS，重点研究可能支配 AF 起始和持续的结构基础。
本研究对 15 例非病变人心肺尸体的肺静脉进行了纵向组织切片研究。使用 H&E 和 Gömöri 三色染色对组织进行组织学研究。使用单克隆 HCN4 和 HCN1 抗体通过免疫组织化学鉴定起搏通道。
在每个肺静脉中均识别出 AMS，位于外膜和中膜之间。在 30%的静脉中，AMS 内可见类似节段的心肌排列。它有一个由纤维囊限制的致密区，包含更小、更苍白和相互连接的心肌。在胶囊外，有一个离散的、单个放置的心肌区，将致密区与 AMS 的工作心肌隔开。HCN4 和 HCN1 抗体在节段性心肌细胞的细胞膜上表达，而工作心肌细胞则表现出无到最小的染色。
肺静脉结在致密区和过渡区的组织排列、细胞特征和起搏通道的存在上与心脏的特殊传导组织相似。它们可能是异位心律失常灶的解剖学基础。据我们所知，这些结在人类中是首次被描述。
