Ⅰ导联R/(R+S)对胸前V3导联移行流出道室性心律失常起源部位的鉴别价值

Value of leadⅠR/(R+S)ratio in identifying origin of outflow tract ventricular arrhythmia with precordial R/S transition at lead V3

目的:探索鉴别胸前V3导联移行流出道室性心律失常(OT-VA)起源部位的体表心电图指标。方法:连续选择2017年1月至2022年8月行导管射频消融术的胸前V3导联移行OT-VA患者65例。比较左室流出道起源组(LVOT组)和右室流出道起源组(RVOT组)室性心律失常发作时体表心电图QRS波振幅及相关指标的差异,选择差异有统计学意义的指标,绘制ROC曲线评价所选取指标鉴别OT-VA起源部位的效能。结果:LVOT组11例,RVOT组54例,两组间差异有统计学意义且ROC曲线下面积(AUC)最大的指标为Ⅰ导联R波/(R+S)波振幅比[R/(R+S)],其鉴别OT-VA起源部位的AUC(95%CI)为0.949(0.894~1.000),截断值为0.50。Ⅰ导联R/(R+S)<0.50诊断胸前V3导联移行LVOT起源OT-VA的敏感度、特异度和准确度分别为0.909、0.944和0.938。结论:Ⅰ导联R/(R+S)<0.50可准确鉴别LVOT起源的胸前V3导联移行OT-VA。

Aim:To explore the indexes of electrocardiography(ECG)that could identify origin of outflow tract ventricular arrhythmia(OT-VA)with precordial R/S transition at lead V3.Methods:This study consecutively enrolled 65 OT-VA patients with precordial R/S transition at lead V3 who underwent successful radiofrequency catheter ablation between January 2017 and August 2022.We compared the QRS wave amplitudes and the related indexes in the surface ECG between left ventricular outflow tract(LVOT)and right ventricular outflow tract(RVOT)groups.ROC curve was drawn based on the significant indexes between the 2 groups and a new diagnostic method was developed.Results:The origin sites of 11 patients were LVOT and those of 51 patients were RVOT.The leadⅠR/(R+S)ratio was significantly lower in LVOT group than that in RVOT group(P<0.001).The AUC(95%CI)of leadⅠR/(R+S)ratio,which had the largest AUC for identifying LVOT origin,was 0.949(0.894-1.000),and the cut-off was 0.50.The leadⅠR/(R+S)ratio<0.50 was applied to identify LVOT origin,and the sensitivity,specificity and accuracy were 0.909,0.944 and 0.938,respectively.Conclusion:LeadⅠR/(R+S)ratio<0.50 could be applied to identify LVOT originating OT-VA with precordial R/S transition at lead V3 accurately.