Zhao Yuanqin, Wan Juyi, Liao Bin, Qi Man
State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, 100037 Beijing, China.
Department of Cardiovascular Surgery, The Affiliated Hospital, Southwest Medical University, Metabolic Vascular Diseases Key Laboratory of Sichuan Province, Key Laboratory of Cardiovascular Remodeling and Dysfunction, 646000 Luzhou, Sichuan, China.
Rev Cardiovasc Med. 2025 Apr 22;26(4):27882. doi: 10.31083/RCM27882. eCollection 2025 Apr.
The existence of internodal tracts (ITs) is controversial. Indeed, ITs in the cardiac conduction system (CCS), connected to the sinoatrial node (SAN), transmit electrical signals quickly to the left atrium and the atrioventricular node (AVN). Interestingly, research has suggested that the ITs and the tail of the SAN may share developmental homology. Additionally, many studies indicate that ITs blockage can lead to atrial conduction block and is associated with atrial fibrillation (AF). However, few studies have been reported on the morphogenesis, development, and function of ITs. Therefore, this paper aims to review the morphogenesis, development, and function of ITs, focusing on the regulatory mechanisms of transcription factors (TFs), such as NK2 homeobox 5 (NKX2.5), SHOX homeobox 2 (SHOX2), hyperpolarization activated cyclic nucleotide gated potassium channel 4 (HCN4), and T-box transcription factor 3 (TBX3) in the development and morphogenesis of ITs. This review also explores the causes of arrhythmias, especially atrial block, in order to provide new insights into the pathogenesis of CCS disorders.
结间束（ITs）的存在存在争议。实际上，心脏传导系统（CCS）中与窦房结（SAN）相连的结间束能迅速将电信号传导至左心房和房室结（AVN）。有趣的是，研究表明结间束和窦房结尾部可能具有发育同源性。此外，许多研究表明结间束阻滞可导致心房传导阻滞，并与心房颤动（AF）相关。然而，关于结间束的形态发生、发育和功能的研究报道较少。因此，本文旨在综述结间束的形态发生、发育和功能，重点关注转录因子（TFs）的调控机制，如NK2同源盒5（NKX2.5）、短指/矮小同源盒2（SHOX2）、超极化激活环核苷酸门控钾通道4（HCN4）和T盒转录因子3（TBX3）在结间束发育和形态发生中的作用。本综述还探讨了心律失常尤其是心房阻滞的病因，以便为心脏传导系统疾病的发病机制提供新的见解。
