胸导联R／S波振幅转换及V2导联R波振幅比例比较在判断室性心律失常左右流出道起源中的价值

目的 探讨通过比较流出道室性心律失常（OTA）及窦性心律（SR）时胸导联R/ S波振幅转换及V2导联R波振幅比例变化,判断OTA起源于右室流出道（RVOT）或左室流出道（LVOT）的价值。方法 回顾性分析208例经射频导管消融治疗成功证实的起源于RVOT或LVOT的OTA患者的ECG特点。观察OTA时发生R/ S转换的胸前导联,发生在V3以前判定OTA起源于LVOT;R/ S转换发生在V3导联时,比较OTA及SR时V2导联R波振幅比例,如V2转换率大于1则判定OTA起源于LVOT;R/ S转换发生在V3以后时判定OTA起源于RVOT。统计各诊断方法的灵敏度、特异度。结果 208例患者中男性76例,年龄43. 6±13. 8岁。 OTA的成功射频消融靶点位于RVOT者181例,位于LVOT者27例。 OTA时ECG形态表现R/ S转换在V3以前的患者18例,起源于LVOT者17例。以OTA的R/ S转换早于V3即诊断OTA起源于LVOT为标准,其灵敏度为63. 0% ,特异度99. 5%。 OTA时ECG形态表现R/ S转换在V3以后的共112例,均起源于RVOT。以OTA的R/ S转换晚于V3即诊断OTA起源于RVOT为标准,其灵敏度为61. 9%,特异度100%。 OTA的ECG形态表现R/ S转换在V3的患者78例,起源于RVOT 68例。起源于LVOT的V2转换率大于起源于RVOT的V2转换率（1. 32±0. 26 vs 0. 52±0. 20,P〈0. 05）。 OTA的R/ S转换在V3时,如果以V2转换率≥1即诊断OTA起源于LVOT为标准,其灵敏度80. 0% ,特异度94. 2%。OTA时R/ S转换在V3而SR时R/ S转换在V2的患者共22例,均起源于RVOT,此方法灵敏度32. 4%,特异度100%。结论 OTA的胸前导联R/ S转换早于V3和晚于V3作为诊断OTA起源于LVOT和RVOT的标准具有很高的特异度和灵敏度。 OTA时R/ S转换在V3时,比较OTA及SR时V2导联R波振幅比例,如V2转换率大于1则判定OTA起源于LVOT具有较高的实用价值。

The value of comparing R/S wave amplitude transition and lead V2 R-wave amplitude ratio in distinguishing the origins from right and left ventricular outflow of ventricular arrhythmias

Objective To investigate the value of comparing R/S wave amplitude transition and lead V2 R-wave ampli- tude ratio during sinus ryhthm （SR） and outflow tract arrythmia （OTA） in distinguishing the origins from right and left ventricular outflow tract of ventricular arrhythmias. Methods ECG characteristics were retrospectively analyzed in 208 consecutive patients with left or right ventricular outflow tract（ LVOT or RVOT） arrhythmia origin confirmed by successful radiofrequency catheter ablation. R/S transition lead was checked in every patient. OTA origin was judged as from LVOT if R/S transition occured before lead V3 and from RVOT if R/S transition occured after lead V3. Lcad V2 R-wave amplitude ratios were compared during SR and OTA if R/S transition occured at lead V3 lead. OTA origin was judged from LVOT if lead V2 ＇s transition ratio during OTA was more than 1. 0. The specificity and sensitivity of each method was calculated. Results There were 76 men with OTA and the mean age was 43.6± 13.8 year-old in 208 patients. OTAs were successfully ablated from RVOT in 181 patients and from LVOT in 27 patients. There were 18 cases with OTA morphology of R/S transition before lead V3 and the OTAorigins were located at LVOT in 17 patients. The criterion of R/S transition before lead V3 for judgment of OTA origin from LVOT were with the specificity of 99.5% and the sensitivity of 63.0%. There were 112 cases with OTA morphology of R/ S transition after lead V3 and OTA origins were from RVOT in all these patients. The criterion of R/S transition after lead V3 for prediction of OTA origin from RVOT were with the specificity of 100% and the sensitivity of 61.9%. There were 78 cases with OTA morphology of R/S transition in lead V3 and the OTA origins were located at LVOT in 10 patients and at RVOT in 68 patients. V2 ＇s transition ratio of OTA with LVOT origin was larger than that of OTA with RVOT origin （ 1.32 ±0.26 vs. 0.52±0.20, P〈0.05）. In patients with OTA morphology of R/S transition in lead V3, if V2＇s transition ratio greater than 1.0 was the criterion of the judgment of OTA origin from LVOT ,the specificity would be 94.2% and the sensi- tivity would be 80.0%. However, if V2 ＇s transition ratio greater than 0.6 was the criterion of the judgment of OTA origin from LVOT, the specificity would be 66.2% and the sensitivity would be 100%. In these 78 cases with OTA morphology of R/S transition in lead V3 , there were 22 patients with SR morphology of R/S transition in lead V2 and OTA was originated from RVOT in all these 22 patients. If OTA morphology of R/S transition in lead V3 and SR morphology of R/S transition in lead V2 was the criterion of the judgment of OTA origin from RVOT, the specificity would be 100% and the sensitivity would be 32.4%. Conclusions The specificities and sensitivities of the criterion of identifying the origin of OTA from LVOT by R/S transition before lead V3 and the criterion of identifying the origin of OTA from RVOT by R/S transition after lead V3 were both high. In patients with R/S wave transition in lead V3 , V2 ＇s transition ratio played an important role in lo- cating the origin of OTA. Setting lead V2＇ s transition ratio 1〉 1.0 as a criterion for predicting OTA origin from LVOT was more accurate than setting V2 ＇s transition ratio 〉10.6 as a criterion in this group of patients.