兔肺静脉心肌袖与心律紊乱相关的形态学研究

Morphological study on cardiac dysrhythmia-associated myocardial sleeves of pulmonary veins in rabbits

目的观察肺静脉心肌袖的组织学形态特性,以了解异位兴奋和局灶性房颤起源于肺静脉的形态学基础。方法取20只健康家兔的左心房和肺静脉,通过HE染色、Masson染色进行组织学研究,并用图像分析比较形态学差异。结果肺静脉心肌袖心肌纤维集合成束,走行不规则、方向各异;心肌袖组织中可观察到染色浅淡的苍白样细胞,与P细胞相似,成群或成对孤立存在;横切面肺静脉心肌袖心肌细胞的胞浆面积小、核面积小、核浆比值小、核圆形度大、核周长短,与左心房心肌细胞比较,差异有统计学意义(P<0.01)。结论肺静脉根部存在心房肌的延伸即心肌袖,其心肌纤维分布不均匀,走行方向各异,可能是电传导不均一、各向异性的原因;苍白样细胞的存在可能是引发异位兴奋和局灶自律性升高的形态学基础;肺静脉心肌袖心肌细胞体积较小,胞核较圆。

Objective To investigate the mechanism of ectopic excitation and focal atrial fibrillation originated from pulmonary（PVs） via observing the histological features of myocardial sleeves of rabbit PVs. Methods qqae PVs and left atria from 20 adult rabbits were stained with l＇~natoxylin and rosin, and Ma^on trichrtxne stain, followed by computer-assisted image analysis. Results The muscle tilers in myocardial sleeves were assembled with fasciculation and extended irregularly. The grouped or paired pale cells, like P cells, were distributed in my-ocardial sleeves. Compared with the left atrium, the plasmic and nuclear area, karyopla.ratic ratio and nuclear perimeter decreased, and the circular measure incressed in the myocardial cells of myocardial sleeves （P〈0.01）. Conclusion The myocardial fibers are irregularly arranged in myocardial sleeves of rabbit PVs, which may cause the electric conduction unevenly and nonisotropically. The pole cells could be related to the ectopic excitation and focal autorhythmicity. The myocardial cells are small, and their nuclei are round in myocardial sleeves as compared with the left atrium.