摘要目的:本研究旨在探究微伏级T波电交替（MTWA）对心脏再同步治疗（CRT）患者远期快速性室性心律失常（VTA）发生的预测价值。方法:本研究为诊断性试验研究。选取自2010年5月至2015年1月于南京医科大学第一附属医院心血管内科成功植入心脏再同步治疗起搏器（CRT-P）或心脏再同步治疗除颤器（CRT-D）的慢性心力衰竭（CHF）患者45例，年龄（59.5±12.3）岁，男33例（73.3%，33/45）。所有患者均于术前和术后6个月接受超声心动图和心电图检查，采用活动平板时域法于术后1周内和6个月时在双心室（BiV）110次/min起搏频率下测定MTWA。VTA事件均采自程控仪调取的CRT-P或CRT-D记录的持续性室性心动过速（室速）、心室颤动（室颤），包括抗心动过速起搏（ATP）、电复律（CV）或电除颤治疗的事件，随访（55.3±34.2）个月。按照有无发生VTA事件将患者分为VTA组（A组）和无VTA组（B组）。结果:①CRT对CHF患者左心室射血分数（LVEF）及MTWA的影响：a.两组患者术后6个月LVEF较基线均明显增高[A组：（36.8%±9.8%）对（30.0%±7.1%）， P=0.004；B组：（44.1%±12.7%）对（31.5%±7.6%）， P<0.001]；b.两组患者术后6个月MTWA（MTWA2）较基线MTWA（MTWA1）均有下降，但差异无统计学意义。②MTWA对CRT术后远期VTA发生的预测价值：a.基线和术后6个月A组患者的MTWA值明显大于B组[MTWA1：（26.6±21.0）μV对（11.4±6.8）μV， P=0.002；MTWA2：（19.0±15.4）μV对（9.8±10.0）μV， P=0.02]。b.以22 μV和13 μV分别作为MTWA1和MTWA2的分界点，将患者分为MTWA阳性组与阴性组，基线与术后6个月MTWA阳性组患者VTA的发生率均明显大于MTWA阴性组（基线， P=0.002；术后6个月， P=0.012）。MTWA1以22 μV为最佳分界点，预测VTA事件的敏感性为47.6%，特异性为95.8%；MTWA2以13 μV为最佳分界点，预测VTA事件的敏感性为61.9%，特异性75.0%。c.用Log rank法对VTA发生时间分布的差异进行检验：MTWA1阳性组、MTWA2阳性组发生VTA的时间比同组阴性组发生时间明显缩短。d.采用二分类Logistic回归分析评估MTWA1、MTWA2与LVEF对VTA的影响，结果显示相对于LVEF，MTWA值对VTA的发生具有更好的预测作用。 结论:MTWA对CRT患者远期VTA的发生有良好的预测价值。

abstractsObjective:To explore the predictive value of microvolt T-wave alternation (MTWA) for long-term ventricular tachyarrhythmia (VTA) after cardiac resynchronization therapy (CRT) .Methods:This research was a diagnostic test research. This study enrolled 45 patients with chronic heart failure (CHF) who were successfully implanted with cardiac resynchronization therapy pacing (CRT-P) or cardiac resynchronization therapy defibrillator (CRT-D) from May 2010 to January 2015 in department of cardiology in the First Affiliated Hospital of Nanjing Medical University[mean age: (59.5±12.3) years old], including 33 males (73.3%, 33/45) . All patients underwent echocardiography and electrocardiogram preoperatively and 6 months postoperatively. MTWA values ??were measured at a biventricular (BiV) pacing rate of 110 beats per minute within one week and six months after device implantation using modified moving average analyses. VTA events, including sustained ventricular tachycardia, ventricular fibrillation, anti-tachycardia pacing (ATP) or cardioversion (CV) or shock therapy were collected from the device. The average follow-up time was (55.3±34.2) months. According to the presence or absence of VTA events, all patients were divided into VTA group (Group A) and non-VTA group (Group B) .Results:①The effect of CRT on left ventricular ejection fraction (LVEF) and MTWA in CHF patients: a.The LVEF ??of two groups were significantly improved at six-month follow-up than baseline[Group A: (36.8%±9.8%) vs. (30.0%±7.1%) , P=0.004; Group B: (44.1%±12.7%) vs. (31.5%±7.6%) , P<0.001]. ｂ. The MTWA value at six-month (MTWA2) decreased compared to the baseline MTWA (MTWA1) in two groups, but there was no statistical difference. ②The predictive value of MTWA for long-term VTA: a.The MTWA of Group A at baseline and six months was significantly higher than that of Group B[MTWA1: (26.6±21.0) μV vs. (11.4±6.8) μV, P=0.002; MTWA2: (19.0±15.4) μV vs. (9.8±10.0) μV, P=0.02) . b.Using 22 μV and 13 μV as the cut-off point for MTWA1 and MTWA2 respectively, all patients were divided into MTWA positive group and negative group. The probability of VTA in the MTWA positive group at baseline and six months was significantly greater than that in the MTWA negative group (baseline: P=0.002; six months after surgery: P=0.012) . The sensitivity of MTWA1 for predicting VTA events was 47.6%, and the specificity is 95.8%. The sensitivity of MTWA2 for predicting VTA events was 61.9 %, and the specificity was 75.0%. c.Log rank method was used to test the difference in time distribution of VTA occurrence. The time of occurrence of VTA in the MTWA1 positive group and MTWA2 positive group was significantly shorter than that of the negative group. d.Two-category Logistic regression was used to evaluate the effects of MTWA1, MTWA2 and LVEF on the occurrence of VTA. Both Logistic models showed that compared with LVEF, MTWA indicators had a better prediction for VTA. Conclusion:MTWA has a good predictive value for the occurrence of long-term VTA in CRT patients.