目的：探讨致心律失常性心肌病(arrhythmogenic cardiomyopathy，ACM)的组织学和亚细胞学特点及其与临床的关系。方法：对38例因ACM行心脏移植术患者的临床、病理资料进行回顾性研究，分析其临床特征、心脏大体及组织学表现，并对其中7例进行透射电镜观察，寻找组织学表型、超微结构与临床心电表现间的关系。结果：本组ACM病例中右室型(57.9%)最常见，其次为双室型(31.6%)，再次为左室型(10.5%)。右室型组织学改变以脂肪型为主，左室型组织学改变以纤维脂肪型为主(P<0.05)。透射电镜显示本组病例均存在收缩不良、过度收缩、收缩不同步现象，85.7%(6/7)存在闰盘异常，71.4%(5/7)观察到幼稚的心肌细胞或幼稚的细胞器。单纯右室型者发病年龄较左室受累型者年轻(P=0.02)；心律失常类型与解剖定位分型相关(P=0.01)；室性心律失常发生率，双室型者(88.9%)>右室型(42.3%)>左室型(0%)。左室组织学改变与心脏重量增加相关(P<0.01)。左室射血分数(left ventricular ejection fractions，LVEF)与解剖学定位分型及组织学分型均未显示出统计学意义(均P>0.05)。结论：ACM的组织学及超微结构检查有助于本病的病因学诊断，亦为深入进行基因遗传学研究提供形态学依据。
Morphological and ultrastructural study in heart transplantation recipients with arrhythmogenic cardiomyopathy
Objective: To investigate the histopathological and ultrastructural features of arrhythmogenic cardiomyopathy (ACM). Methods: The clinical and pathological data of 38 ACM patients with heart transplantation were retrospectively studied, the clinical characters, gross observation and histopathological findings were analysed. The correlation between the histological type, myocardial ultrastructure changes and clinical electrocardiogram performance in seven cases were identified using transmission electron microscopy. Results: Classical right-dominant subtype (57.9%) was the most common, followed by biventricular forms (31.6%), then left-dominant subtypes with predominant LV involvement (10.5%). The histological changes of classical right-dominant subtypes were mainly fatty replacement, and that of the left dominant subtypes were mainly fibroadipose replacement (P<0.05). Transmission electron microscope found that sarcomere supercontraction, overstretch or myofibril fracture were ubiquity, and abnormality intercalated discs were observed in 85.7% (6/7), immature myocardial cell or organelles could were observed in 71.4%. Patients of classical right-dominant subtypes were younger than that of the other two groups (P=0.02). Arrhythmia types were associated with anatomical classification (P=0.01). The incidence of ventricular arrhythmias: biventricular (88.9%) > RV-dominant (42.3%) > RV-dominant (0%). Histologic changes of left ventricular associated with heart weight increased (P<0.01). The left ventrical ejection fraction (LVEF) did not show a relationship with anatomical type or hishistopathological type(P>0.05). Conclusion: Histological and ultrastructural examination on ACS could help the etiological diagnosis, and also provide the morphological basis for further genetic studies.