Myocyte changes and their left atrial distribution in patients with chronic atrial fibrillation related to mitrat valve disease
Myocyte changes and their left atrial distribution in patients with chronic atrial fibrillation related to mitrat valve disease
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DOI：
10.1016/j.humpath.2005.07.018
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发表时间：
2005-10-01
期刊：
影响因子：
3.3
通讯作者：
Alfieri, O
中科院分区：
文献类型：
--
作者：
Corradi, D;Callegari, S;Alfieri, O
肺静脉及其邻近的左心房后壁（LAPW）与心房颤动（AF）的发生和维持密切相关，对这些高危部位的识别引起了研究其组织病理学基础的极大兴趣。我们采用光镜和常规电镜观察了28例接受二尖瓣手术的慢性房颤患者和12例尸检对照者的LAPW和左心耳（LAA）样本中的不同肌细胞和间质变化，LAPW中的肌节丢失的肌细胞总是多于LAA中的肌节丢失的肌细胞（19.9% +/- 7.7%对8.2% +/- 5.0%; P <0.0001），LAPW显示更明显的去分化免疫组化证据，其特征是平滑肌肌动蛋白的再表达。在病理性左心房中，LAPW和LAA的肌细胞直径相当（19.0 +/- 1.5对18.5 +/- 2.0 μ m;不显著），但大于对照组（分别为11.9 +/- 0.8和12.1 +/- 1.3 μ m; P <0.0001）。末端脱氧核苷酸转移酶试验未发现任何心肌细胞凋亡。LAPW的间质纤维化程度也高于LAA（7.49% +/- 3.34% vs 2.80% +/- 1.35%; P <0.0001）。超微结构检查证实了存在的肌细胞myocytolysis在核周区，并显示线粒体形状的变化。总之，与二尖瓣疾病相关的慢性房颤患者的LAPW似乎是一个特殊的解剖部位，其中主要的肌细胞和间质的变化集中，而左心耳更受保护。这种重塑可能会增加LAPW电传导的异质性，从而证实该位置是AF消融治疗的选择性靶点。（c）2005年Elsevier Inc. All rights reserved.
It has been found that the pulmonary veins and adjacent left atrial posterior wall (LAPW) are deeply involved in both the initiation and maintenance of atrial fibrillation (AF), and the identification of these high-risk sites has aroused great interest in investigating their histopathologic substrate. We used light and conventional electron microscopy to evaluate the differential myocyte and interstitial changes in LAPW and left atrial appendage (LAA) samples from 28 patients with chronic AF undergoing mitral valve surgery and from 12 autoptic controls.There were always more myocytes with loss of sarcomeres in the LAPW than in the LAA (19.9% +/- 7.7% versus 8.2% +/- 5.0%; P < .0001), and the LAPW showed more marked immunohistochemical evidence of dedifferentiation, characterized by the reexpression of smooth muscle actin. In pathological left atria, myocyte diameter in the LAPW and LAA was comparable (19.0 +/- 1.5 versus 18.5 +/- 2.0 mu m; not significant) but larger than in the controls (11.9 +/- 0.8 and 12.1 +/- 1.3 mu m, respectively;, P < .0001). A terminal deoxynucleotidyltransferase assay did not reveal any myocyte apoptosis. The LAPW also showed more interstitial fibrosis than the LAA (7.49% +/- 3.34% versus 2.80% +/- 1.35%; P < .0001). Ultrastructural examination confirmed the presence of myocyte myocytolysis in the perinuclear area and showed changes in mitochondrial shape.In conclusion, the LAPW in patients with chronic AF related to mitral valve disease seems to be a particular anatomical site in which major myocyte and interstitial changes are concentrated, whereas the LAA is more protected. This remodeling may increase the heterogeneity of LAPW electrical conduction, thus confirming this location as an elective target for the ablation treatment of AF. (c) 2005 Elsevier Inc. All rights reserved.