目的　探讨儿童预激性心肌病的发病机制、诊断及射频消融治疗效果。方法　回顾分析1例确诊为预激性心 肌病患儿的临床资料。结果　12岁男性患儿，体表心电图示B型预激综合征；心脏彩超示扩张型心肌病，病程中无心动过 速发作；电生理检查示右后间隔旁道。射频消融术后，心电图提示delta波消失，心脏超声显示左心室缩小及心功能改善， 且临床症状明显好转。结论　预激导致左心室兴奋-机械收缩偶联不同步可能是预激性心肌病最重要的发病机制，以右侧 间隔部显性旁道最多见。射频消融治疗有效，预后良好。

　Objective　To explore the pathogenesis, diagnosis and radiofrequency ablation effect of preexcitation cardiomyopathy in children. Method　The clinical data of a preexcitation cardiomyopathy in a child was analyzed retrospectively. Results　In a 12-year-old boy, electrocardiogram showed type B Wolff-Parkinson-White syndrome. Echocardiography showed dilated cardiomyopathy without tachycardia attack during the course of the disease. Electrophysiological examination revealed right posterior septal accessory pathway. After radiofrequency ablation, electrocardiogram showed that the delta wave disappeared and echocardiography showed that the left ventricle size shrank and the cardiac function improved and the clinical symptoms were significantly improved. Conclusion　The non-synchronization of excitation-mechanical contraction coupling in left ventricle caused by ventricular preexcitation may be the most important pathogenesis of preexcitation cardiomyopathy, in which the overt accessory pathway in the right septum is the most common. Radiofrequency ablation is effective and has a good prognosis.