预激综合征对QRS终末向量影响的立体心电向量分析

Effects of pre-excitation syndrome on terminal QRS vector observed in spatial vector

目的:预激综合征影响QRS终末向量,但尚未被关注。本文应用向量图对照分析预激综合征消融旁路前后QRS终末向量变化,探讨终末向量改变与旁路位置及初始向量改变的关系。方法:选择辽宁医学院附属第一医院经导管射频消融术(radiofrequency catheter ablation,RFCA)根治显性单旁路预激综合征患者30例(按旁路部位分为7组)。用卡方检验对照分析RFCA前后QRS初始向量和终末向量的变化,并分析终末向量方位改变与初始向量改变及旁路位置的关系。结果:130例患者RFCA前后对照QRS终末立体向量均有改变:仰角改变25例,水平角改变27例,两者同时改变22例,两者一致性差,Kappa检验无统计学意义(κ=-0.379,P=0.106)。2终末向量改变与旁路位置关系:左室旁路:11/16例表现为水平角绝对值增大。其中左前壁和左侧壁旁路多表现为仰角减小;而左后壁旁路表现为仰角增大。右室旁路:10/14例患者表现为水平角绝对值减小;仰角13/14例增大。终末向量改变与初始向量改变的符合率为91.65%(κ=0.856,P=0.000)。结论:1预激综合征旁路前传不仅影响初始向量同时影响终末向量,终末向量改变与旁路位置和初始向量有关。2立体心电向量分析预激综合征初始向量、终末向量改变优于心电图,有助于心电图表现不典型的预激综合征诊断和旁路位置分析。

Objective：Preexcitation syndrome could affect terminal QRS vector,which is not emphasized in clinic. In this study,we made a comparison between vectorcardiogram（VCG）before and after ablation to observe the change of terminal QRS vector and to explore the relationship between the change of terminal QRS vector and accessory pathway（AP）as well as the change of initial QRS vector（delta vector）. Methods：Thirty patients who were proved to have a single AP by ablation were included in the First Affiliated Hospital of Liaoning Medical College. All patients were divided into 7 groups based on the AP location. Comparison between VCG before and after ablation was made by χ^2analysis to observe the change of terminal and delta vector. The relationship between the change of terminal QRS vector and AP location as well as delta vector was analyzed. Results：①All 30 patients had changes in terminal QRS vector（elevation and/or azimuth）in comparison to post-ablation VCG：Out of 30 enrolled patients,25 had changes in elevation and 27 had changes in azimuth. The consistency between the change of elevation and the change of azimuth was-0.379（P=0.106）.②Relationship between the change of terminal QRS vector and accessory pathway location：An increase of absolute value in azimuth was found in 11 of 16 patients with left-side AP. Decrease of elevation was usually observed in patients with left anterior and left lateral AP. Inversely,an increase of elevation was usually observed in patients with left posterior AP. Out of 14 patients with right-side AP,10 had a decrease of absolute value in azimuth. Thirteen of the 14 patients with right-side AP had an increase in elevation. The agreement and consistency between the change of terminal QRS vector and delta vector were 91.65% and 0.856（P=0.000）respectively. Conclusion：①Both initial and terminal QRS vector are affected by the antegrade conduction of AP. The change of terminal QRS vector is related to the AP location and delta vector. ②QRS terminal vector is superior to ECG in analyzing pre-excitation syndrome,which is helpful for the diagnosis of atypical pre-excitation and localization of AP.