心室预激性扩张型心肌病临床特点分析

Clinical characteristics of ventricular preexcitation dilated cardiomyopathy induced by accessory pathway

目的探讨心室预激性扩张型心肌病的临床特征、诊断方法、发病机制及其预后。方法回顾性分析首都医科大学附属北京安贞医院小儿心脏中心2011年3月至2012年8月诊断的4例心室预激性扩张型心肌病的诊断过程，分析其临床、超声及电生理特点，随访其射频消融术后转归。结果4例患儿体表心电图均提示为B型预激，成功消融靶点2例位于右侧前间隔，另2例位于右侧游离壁。M型超声示室间隔与左心室后壁呈不协调运动，二维超声检查发现室间隔基底段变薄且呈瘤样矛盾运动；斑点追踪技术发现左心室收缩不同步。经成功消融后，体格发育及体力活动量明显改善；超声提示左心室收缩协调，左心功能渐恢复正常，左心室舒张末径明显回缩至正常或接近正常。结论右侧前间隔或游离壁显性旁路可能对室壁运动及左心室功能产生不良影响，严重者可致扩张型心肌病。心室预激致左心室收缩不同步可能是其最重要的发病机制。心室预激性扩张型心肌病为射频消融的适应证，预后良好。

Objective To discuss the characteristics, diagnosis, mechanism and the prognosis of dilated car- diomyopathy（DCM） induced by accessory pathway（AP）. Methods The clinical, electrophysiological and echocardio- graphic characteristics in four cases ,who were diagnosed as AP-induced DCM in the Department of Pediatric Cardiology of Beijing Anzhen Hospital, Capital Medical University from Mar. 2011 to Aug. 2012, were analyzed before and after ab- lation. Results The electrocardiograms of the 4 patients all indicated type B ventricular preexcitation. The locations of the APs were the right-sided anteroseptum and the free wall. Dyschronous contractions between posterior wall of left ven- tricle and interventricular septum were demonstrated by M-Mode echo. The basal segments of the interventricular septum turned thin and moved similar to an aneurysm, with typical bulging during end-systole,which was observed in all cases by two-dimension echo. Dyschronous left ventricular contraction was shown by speckle tracing technique. All patients re- ceived successful radio frequency current ablations. Their physical activities and growth improved greatly in the 4 cases. The echocardiographic data demonstrated that their left ventricular contraction recovered to synchrony shortly after the ablation,left ventricular ejection fraction recovered to normal and left ventricular end diastolic diameter decreased to al- most normal gradually during the follow-up. Conclusions Overt right-sided APs localized in anteroseptum or free wall may have adverse effects on ventricular wall motion and left ventricular function. They can even result in DCM. Dyssyn- chronous ventricular contraction induced by right-sided overt accessory pathway may be the vital mechanism. AP-in- duced DCM is an indication for ablation with good prognosis.