摘要：
Objective To explore the validity of lead aVL in combination with lead V1 for identifying idiopathic outflow tract premature ventricular contractions(PVCs)originating from aortic sinus cusp(ASC).Methods This study consecutively enrolled 102 idiopathic outflow tract PVCs patients who underwent radiofrequency catheter ablation at the Second Xiangya Hospital,Central South University between January 2015 and August 2017.We compared the QRS wave amplitudes in the surface twelve leads electrocardiography between PVCs originating from ASC and right ventricular outflow tract(RVOT).Results(1)The origin sites of PVCs were ASC(n=28,27.5％)and RVOT(n=74,72.5％).The lead V1R/S wave amplitude ratio and lead aVL S wave amplitude were significantly higher in the ASC group than in the RVOT group[(1.14±1.32)vs.(0.16±0.18),P＜0.001;(0.99±0.36)mV vs.(0.56±0.26)mV,P＜0.001].The areas under the receiver operating characteristic curve(AUCs)and 95％confidence intervals of V1R/S wave amplitude ratio and aVL S wave amplitude had relatively larger AUCs which were 0.894(0.824-0.964)and 0.831(0.749-0.912),with the cut-offs of 0.25 and 0.80 respectively.(2)The sensitivity,specificity and accuracy of the lead V1R/S wave amplitude ratio＞0.25 to identify ASC originating PVCs were 78.9％,83.7％and 82.4％,respectively.The sensitivity,specificity and accuracy of the lead aVL S wave amplitude＞0.80 mV were 78.6％,85.1％and 83.3％,respectively.The lead aVL S wave amplitude＞0.80 mV in combination with the lead V1R/S wave amplitude ratio＞0.25 was applied to developed a new diagnostic approach and the sensitivity,specificity and accuracy were 60.7％,93.2％and 84.3％,respectively.Conclusions Lead aVL in combination with lead V1 could be applied to develop a more accurate method for identifying ASC originating PVCs.%目的 探讨aVL导联结合V1导联对鉴别主动脉窦(ASC)起源室性早搏的实用性.方法 连续纳入2015年1月至2017年8月于中南大学湘雅二医院心血管内科住院,行导管射频消融术的特发性流出道室性早搏患者102例.比较起源于ASC与右心室流出道(RVOT)的室性早搏,其12导联体表心电图的QRS波振幅之间的差异.结果 (1)28例(27.5％)室性早搏起源于ASC,74例(72.5％)起源于RVOT.V1导联R/S波振幅比和aVL导联S波振幅为Roc曲线下面积(AUC)最大的两个指标,AUC值及95％CI分别为0.894(0.824～0.964)和0.831(0.749～0.912),界值分别为0.25和0.80;ASC组V1导联R/S波振幅比[(1.14±1.32)比(0.16±0.18),P＜0.001]和aVL导联S波振幅[(0.99±0.36)mV比(0.56±0.26)mV,P＜0.001]均显著高于RVOT组,差异均有统计学意义.(2)V1导联R/S波振幅比＞0.25诊断ASC起源室性早搏的敏感度、特异度及准确度分别为78.6％、85.1％和83.3％;aVL导联S波振幅＞0.80 mV诊断ASC起源室性早搏的敏感度、特异度及准确度分别为67.9％、83.8％和79.4％.aVL导联S波振幅＞0.80 mV联合V1导联R/S波振幅比＞0.25形成诊断ASC起源室性早搏的新方法,其敏感度、特异度及准确度分别为60.7％、93.2％和84.3％,特异度及准确度均明显提高.结论 aVL导联结合V1导联可准确鉴别ASC起源的室性早搏.
