预激综合征体表心电图的旁路定位

Localization of accessary pathways in W-P-W syndrome by 12-lead electrocardiogram

１１４例预激综合征合并室上性心动过速经射频消蚀术治愈。回顾性分析体表心电图各导联定位特征。左侧旁路偏前及偏后者的ａＶＬ和Ⅰ导的δ波依次由负向（－）变正向（＋）。左前及侧位者ａＶＬ导的δ波全部为－。Ⅱ、Ⅲ、ａＶＦ导的δ波则在偏前者为＋，偏后者为－。心前导联全部δ波为＋。主波在Ｖ１导中９１．３％朝上，移行带在Ｖ１或其右侧导联，无１例在Ｖ２及其左侧导联。右侧旁路位者ａＶＬ和Ⅰ导的δ波都是＋，Ⅱ、Ⅲ、ａＶＦ导的δ波偏后者及偏前者依次由－变＋。Ｖ１和Ｖ２导的δ波有十也有－，但Ｖ１导的主波全部向下，移行带在Ｖ２导的左侧者占９５％，仅２例在Ｖ２，无１例在Ｖ１导及右侧。后间隔旁路包括右、左及貌似右侧实在左侧消蚀成功者，其心电图特征不够明显，要求心内精确标测定位。总之，体表心电图定位有助于术前做好技术及物质力量的准备。

Abstract Quite a number of algorithms for the localization of accessary pathways (AP) by surface electrocardiogram have been proposed.In the present paper 114 cases with W-P-W syndrome, the localizations of AP (58 cases on the left side, 56 on the right) have been accurately defined as all of them have been successfully ablated by radiofrequency. All these cases had 12-lead electrocardiogram in sinus rhythm. The localization of AP could be quite accurately designed by retrospective analyses of their electrocardiograms. Three features were found to be essential for the localization, namely (1)Polarity of the delta wave at 40ms (δ40),(2) main direction of the QRS complex, and (3) transitional zone in the precordial leads.The localization of AP should first be determined by simple observation of the electrocardiogram to locate its approximate site. It is very essential that the precordial leads must be recorded at the exactly standard sites.Whether AP is on the left or right side can be located by observation of lead V1 and the position of the transitional zone, and whether AP is located anteriorly or posteriorly has to be determined by the limb leads. Details were summarized in the followings:(1) δ40 in V1 and its main deflection: All the directions of δ40s of the left sided AP were positive, while 1/3 of those of the right sided AP was +, -or ± each. 93.3% of the right sided AP was characterized by a downward (-) main deflection of V1, however, almost 100% of the left main deflection by a upward (+) with a corresponding specificrty of 96. 6%,indicating that Rosenbaums'A,B types proposed in 1945 are still practical in this respect.(2) Transitional zone: The transitional zone in 50 cases of left sided AP (83.6%) was at lead V1 or on its right side (V3r, V4r), while that of 41 cases of right sided AP (73.2%) was either on lead V2 or its left side.There was almost no overlapping. However,in 23 cases (AP on the left side in 8, on the right side in 15) the transitional zone was between leads V1 and V2. Accurate statistic method showed that when the transitional zone is exactly between V1 and V2, right sided AP should be considered in most cases.(3) limb leads:in cases with negative δ40 of lead III and aVF more than 96% of the AP were on the posterior part. When δ40s of these two leads were both positive the AP must be on the anterior part. When the AP is located on the right side δ40 in leads I and aVL are both positive; on the other hand when the AP is either on the left anterior side or on the lateral wall δ40s in these two leads are both negative and when the AP is on the postero-lateral side,δ40s in these two leads are also positive. (4) AP on the septum: This is a special problem. For the right posterior septal, right mid-septal, 'latent' left posteroseptal APs, there is no characteristic finding in the ECG. Therefore in such cases one must carefully search for the AP during ablation. Right antero-septal AP corresponds to the characterisitics of right sided AP, δ40s in limb leads are all positive and the main deflections are upward.Preliminary estimation of the locations of the accessory pathway by careful observation of the surface ECG is quite helpful for subsequent radiofrequency ablation both for the technical personnel and the preparation of necessary equipments.