右室流出道不同部位起搏体表心电图的形态特征研究

右室流出道 (RVOT)是一个相对较大的区域 ,事先定位这一区域内心律失常的起源部位有助于指导射频消融治疗。为评估根据体表 1 2导联心电图定位起源于RVOT不同部位的心律失常 ,选择 90例无器质性心脏病的室上性心动过速患者 (57例房室折返性心动过速、33例房室结折返性心动过速 )进行研究。将RVOT分为游离壁和间隔 ,按距肺动脉瓣的距离由近至远再分上、中、下三部 ,共 6个区。成功进行射频消融后 ,于RVOT不同部位进行起搏 ,并同时记录 1 2导联体表心电图。结果 :在间隔和游离壁起搏时 ,Ⅰ、aVL导联表现为特征性变化。间隔部起搏时Ⅰ导联QRS波形态多变 ,aVL导联QRS波主要呈QS型 ,QRSⅠ/QRSaVL<1 ;在游离壁起搏时 ,Ⅰ导联QRS波主要呈R型 ,aVL导联QRS波形态多变 ,QRSⅠ/QRSaVL>1。Ⅰ、aVL导联QRS波形态特征对判断游离壁和间隔具有较高的特异度和灵敏度。在RVOT上、中、下位起搏时 ,V3导联呈特征性变化 ,分别主要呈R、RS(R/S >1 )、rS(r/S <1 )型。V3导联QRS波形态特征对判断RVOT的上、中、下位具有较高的特异度和灵敏度。结论 :可根据体表心电图图形特征 ,定位RVOT起源的心律失常部位

The Study of Charactristics of Body-Surface Electrocardiogram During Pacing in Different Site in Right Ventricular Outfolw Tract

Right ventricular outflow tract(RVOT) is a relatively large area.The origi n sites of arrhythmias rising from this area should be more preciously localized in order to guide catheter ablation of the arrhythmias.This study validated the value of body-surface 12-lead electrocardiogram(ECG) for localizing the origi n site of arrhythias rising from RVOT.Ninety patients with normal cardiac struct ure and function,57 patients with atrioventricular reentrant tachycardia and 33 patients with atrioventricular nodal reentrant tachycardia,were included.After r adiofrequency catheter ablation was successfully performed,RVOT were divided int o six zones:the upper,middle,and lower zones of septum and free-wall.Subendocar dium pacings were performed in these zones and body-surface 12-lead ECGs were simul taneously recorded.Results:Pacing in free-wall and septum of RVOT,charactic pa tterns of QRS complex occurred in lead Ⅰ and lead aVL of body-surface ECG.Paci ngs in different zones in free wall resulted in R type QRS complex in lead Ⅰ,an d the QRS waves were significantly higher compared with septum zones(0.65±0.14 vs 0.22±0.13 mV, P<0.01 ).QRS Ⅰ to QRS aVL was more than 1;while pacin g in septum,the ratio was less than 1.Pacing in upper,middle,and lower zones of RVOT,QRS complex in V 3 lead of body-surface ECG had a charactic pattern.R typ e QRS complex occurred when pacing in upper zones,rS(rS<1) type QRS complex in l ower zones and RS type(R/S>1) complex in middle zones.Conclusion:Pacings in diff erent zones of RVOT result in different QRS complexes in body-surface ECG and E CG is of certain value for localizing the origin of arrhythias rising from RVOT.