心电图P波形态变化在典型心房扑动射频消融中意义的再评价

目的以峡部消融线上标测到稳定的宽间期双电位作为典型心房扑动(AFL)射频消融(RFCA)终点标准,对消融前后低侧位右房与冠状窦口刺激心电图P波形态变化进行比较,进而评价其临床应用意义。方法24例典型AFL患者,进行三尖瓣环至下腔静脉之间的线性消融。消融后于消融线标测双电位。消融前后,以及消融过程中分别进行低侧位右房与冠状窦口刺激,比较心电图P波形态的变化。结果RFCA成功后行低侧位右房及冠状窦口起搏,所有患者体表心电图Ⅱ,Ⅲ,aVF导联的P波在负向成分之后出现一正向波成分(100%),且P波时限延长,但是6例患者出现特征性心房激动顺序变化时(即低侧位右房刺激时呈顺钟向传导,逆钟向阻滞。冠状静脉窦刺激时呈逆钟向传导,顺钟向阻滞),消融线局部双电位为71.0±11.2ms,此时低侧位右房与冠状静脉窦口刺激也出现相同的P波变化,继续消融可见双电位延长至118.20±10.2ms,而再予刺激,并不出现P波形态的进一步变化(25%)。结论:对于典型AFL的射频消融治疗,峡部消融后进行峡部两侧刺激可以产生心电图P波形态的特征性变化。但是由于峡部为缓慢传导或者残存传导裂隙时也可以出现此种变化,加之影响P波形态的因素较多,所以这种判断方法临床实践应用的意义不大。

Reevaluation of the P wave morphology in detection of typical atrid flutter during ablation

Introduction Different conduction during coronary sinus and posterolateral right atrium pacing may cause a different P wave morpyology after posterior isthmus ablation,which was used to demonstrate complete bi-directional isthmus conduction block (CBIB),in patients with typical atrial flutter(AFL).In comparison with double potenrial (DP) along the ablation line,we reevaluate its significance on the CBIB.Methods In 24 consecutive patients.typical AFL ablations were performed.Activation mapping at both sides of the ablation line during coronary sinus and posterlateral right atrium pacing,which showed absence of pulse propagation via the isthmus,was analyzed first.P wave morphology and duration was simultaneously observed.And mapping of the widely spaced DP was regard as the endpoint for CBIB.Results Positive morphology changes of the terminal P waves and increment of P wave duration,mainly in the inferior leads,were observed when targets of activation mapping were achieved(100%).However,subsequent mapping of DP showed residual conduction in 6 patients(25%),and ablation was continued till the DP>100ms,But no more changes of P wave were observed.Conclusion:The P wave changes after CBIB are common phenomenon with high sensitivity.However,the analysis of P wave morphology and duration as a way to detect CBIB are unnecessary for its low specificity.