Histologically, the cardiac conduction network is formed of electrically isolated subendocardial fibers that comprise specialized cells with fewer myofibrils and mitochondria than cardiomyocytes. Our aim is to uncover regional variations of cardiac conduction fibers through histological and morphometric study in a porcine and human model. We analyzed five male adult human hearts and five male pig hearts. The left ventricles were dissected and sectioned in the axial plane into three parts: basal, middle third and apex regions. Cardiac conduction fibers study was carried out using hematoxylin-eosin and Masson's trichrome staining, and cardiac conduction cells and their junctions were identified using desmin, and a PAS method. Cardiac conduction fibers were difficult to pinpoint in humans, mostly showing a darker color or equal to cardiomyocytes. Cardiac conduction fibers in humans were in the subendocardium and in pigs in the myocardium and subendocardium. Cardiac conduction fibers were located mainly in the septal region in both humans and pigs. In our morphometric analysis, we were able to determine that cardiac conduction cells in humans (18.52 +/− 5.41 μm) and pigs (21.32 +/− 6.45 μm) were large, compared to cardiomyocytes. Conduction fiber-myocardial junctions were present in 10% in humans and 24.2% in pigs. The performance of immunohistochemical methods made it possible to improve the identification of cardiac conduction cells in the species studied. Study of cardiac conduction fibers and cells and their myocardial junctions is vital to gain insight into their normal distribution in the species analyzed, and thus advance the use of pigs in experimental models of the cardiac conduction system in humans.

在组织学上，心脏传导网络由电隔离的心内膜下纤维形成，这些纤维包含比心肌细胞更少的肌原纤维和线粒体的特化细胞。我们的目标是通过猪和人体模型中的组织学和形态测量研究来揭示心脏传导纤维的区域变化。我们分析了五颗成年男性心脏和五颗雄性猪心脏。左心室被解剖并在轴向平面上分成三部分：基底区、中三分之一区和顶点区。使用苏木精-伊红和马森三色染色进行心脏传导纤维研究，使用结蛋白和 PAS 方法鉴定心脏传导细胞及其连接点。心脏传导纤维在人类中难以确定，大多呈现较深的颜色或等于心肌细胞。人的心脏传导纤维位于心内膜下，猪的心肌和心内膜下。心脏传导纤维主要位于人和猪的隔膜区域。在我们的形态测量分析中，我们能够确定与心肌细胞相比，人类 (18.52 +/- 5.41 μm) 和猪 (21.32 +/- 6.45 μm) 的心脏传导细胞较大。传导纤维-心肌连接在人类中的比例为 10%，在猪中为 24.2%。免疫组织化学方法的性能使得提高对所研究物种中心脏传导细胞的识别成为可能。研究心脏传导纤维和细胞及其心肌连接对于深入了解它们在所分析物种中的正常分布至关重要，