慢性心房颤动患者心房肌结构重构的研究

The structural remodeling of atrial myocardium in patients with chronic atrial fibrillaton

目的:研究心房肌结构重构在心房颤动(房颤)发生和维持中的作用。方法:慢性房颤患者10例,对照组6例。应用超声心动图测量房颤患者左右心房内径;应用透射电镜观察左房肌细胞超微结构改变;采用三电极直流等离子体原子发射光电直读光谱法测定心房肌细胞内Ca2+含量。结果:房颤患者心房内径扩大犤左房(63±11)mm;右房(64±14mm)犦;肌原纤维排列紊乱,肌节长短不一,结构模糊,线粒体丛状聚集,嵴异形明显,糖原聚集,润盘扭曲,肌浆网肿胀、破裂;心房肌细胞内Ca2+含量明显高于对照组犤(1330±770)μg/mlvs(302±31)μg/ml,P<0.01)犦。结论:心房肌结构重构可能在慢性房颤的发生和维持中起重要作用,是慢性房颤患者转为窦性心律后心房收缩功能延迟恢复的主要原因,房颤电重构和结构重构之间可能存在联系。

Objective:To evaluate the role of structural remodeling of atrial myocardium in pa-tients with chronic atrial fibrillation(AF).Methods:Ten patients with chronic AF and6control sub-jects were included.The diameter of left and right atrium was measured by echocardiography.The a-trial myocardium was examined by electron microscopy.The content of intracellular calcium was as-sayed by spectrocomparator.Results:The diameter of atrium was lengthene .left atrium was(63±11)mm;right atrium was(64±14)mm.At the ultrastructural level,atrial myocytes from patients with chronic AF showed remarked changes,such as disorganized sarcomere,changes in mitochomdrial shape and size,accumulation of glycogen,tortuous intercalated disc,and fragmentation of sarcoplasmic reticu-lum.The Ca 2+ concentration was significantly increased in patients with chronic AF compared with that in the control(1330±770)μg/ml vs(302±31)μg/ml ,P<0.01).Conclusion:The structural remodeling of atrial myocardium plays an important role in perpetuation of the AF.These structural changes may explain the depressed contractile function of atrial myocardium after cardioversion.The internal correla-tion between electrical remodeling and structural remodeling may exist.