体表心电图P波极向对儿童局灶性房性心动过速起源的定位分析

Use of P-wave polarity during atrial tachycardia to predict site of origin in children

目的 探讨体表心电图P波极向对儿童局灶性房性心动过速（房速）起源位置的解剖定位.方法 清华大学第一附属医院心脏中心小儿科2009年1月至2014年4月连续住院接受射频消融治疗的40例局灶性房速患儿,其中男14例、女26例;年龄（8±3）岁.回顾性分析40例患儿12导联体表心电图P波极向特点,以T-P间等电位线为基准,P波极向分为正向、负向、等电位及双向;分析对应的心房起源位置,对P波极向与起源位置进行x2检验.结果 儿童局灶性房速心电图P波区分左、右心房起源差异有统计学意义的导联为V1、Ⅰ（x2=23.509、14.315,P=0.000、0.001）;源于左心房的房速P波于V1导联均为正向或等电位;源于右心房的房速P波于Ⅰ导联均为正向或等电位.心电图P波极向区分心房上、下部差异有统计学意义的导联为Ⅱ、Ⅲ、aVR、aVF（x2=26.447、23.974、19.613、17.415,P均=0.000）;源于心房上部的房速P波于Ⅱ、Ⅲ、aVF导联多为正向,分别为95％（21/22）、86％（19/22）、95％ （21/22）,于aVR导联多为负向,为73％ （16/22）;18例源于心房下部的房速,12例P波于Ⅱ、Ⅲ、aVF导联为负向,11例于aVR导联为正向.儿童局灶性房速病灶主要分布于右心耳（23％,9/40）,冠状静脉窦口（18％,7/40）,左心耳（15％,6/40）,右上肺静脉（10％,4/40）.结论 儿童局灶性房速多起源于左、右心耳,冠状静脉窦口、肺静脉等位置.心电图的P波极向区分左、右心房起源有显著预测价值的导联为V1及Ⅰ导联;区分心房上、下部起源有显著意义的导联为Ⅱ、Ⅲ、aVR、aVF导联.

Objective To perform a detailed analysis of the P-wave polarity in focal atrial tachycardia （FAT） on the basis of surface electrocardiograms （ECGs） and construct an algorithm for identification of the anatomic site of origin in children.Method P-wave polarities for 40 consecutive children（14 boys and 26 girls,mean age of（8 ± 3）years） with FAT undergoing successful radiofrequency ablation of a single atrial focus at First Hospital of Tsinghua University （2009-2014） were analyzed retrospectively from 12-lead ECGs during tachycardia.P waves were classified as positive,negative,isoelectric,or biphasic.The relations between P-wave and anatomic site of origin were analyzed using a chisquare test.Result The P-wave polarities in leads V1 （x2 =23.509,P =0.000） and Ⅰ （x2 =14.315,P=0.001） were significantly helpful in distinguishing left from right atrial origin of the tachycardia focus.The P-wave in lead V1 of a left atrial tachycardia was always positive or isoelectric in tachycardia.The P-wave in lead Ⅰ of a right atrial tachycardia was always positive or isoelectric during tachycardia.The P-wave polarities in leads Ⅱ,Ⅲ,aVR and aVF （x2 =26.447,23.974,19.613,17.415,all P =0.000）distinguished superior from inferior atrial foci significantly.Tachycardia arising from the superior foci （n =22） had positive P waves in leads Ⅱ,Ⅲ and aVF （95% （n=21）,86% （n=19）,95% （n=21）,respectively） and negative P wave in lead aVR （73%,n =16）.The P-wave was frequently negative in leads Ⅱ,Ⅲ and aVF（n =12） and positive in lead aVR （n =11） for a tachycardia arising from the inferior foci （n =18）.The anatomic sites of FAT in children located mainly at right atrial appendage （23%,n =9）,coronary sinus （18%,n =7）,left atrial appendage （15%,n =6） and right superior pulmonary vein （10%,n =4）.Conclusion The anatomic sites of FAT in children are located mainly at right and left atrial appendage,coronary sinus and right superior pulmonary vein.P-waves in leads V1 and Ⅰ prove to besignificantly useful in differentiating left from right atrial tachycardia foci.P-waves in leads Ⅱ,Ⅲ,aVR and aVF are helpful in distinguishing superior from inferior atrial foci.