在常规运动试验中以时域法微伏级T波电交替筛查冠心病的价值

摘要

Objective:To investigate the value of microvolt T wave alternates(MTWA) in screening the patients with coronary artery disease(CAD).Methods: Our research included two groups, CAD group, n = 152, the patients were diagnosed by coronary angiography, and Control group,n= 140 ,the patients without CAD.MTWA was detected with GE Marquette Case 800 MTWA analyzing system,the maximum amplitude of MTWA and heart rate(HR) were recorded.MTWA/HR ratio was calculated.Results:MTWA and MTWA/HR ratio were higher in CAD group than that in Control group(22.04±7.22) μV vs.( 10.63±6.71 )μV and(0.21±0.08)vs.(0.09±0.06) ,the threshold of HR was lower in CAD group than that in Control group( 107.61±12.06 ) bpm vs.( 126.23 ±9.42) bpm, P＜0.01 respectively.The area under curve of MTWA was 0.908 ( 95 ％ CI 0.87 ～ 0.946, P ＜0.01 ) ,the optimal cut-off value for screening CAD was 11.5 μV( sensitivity 97.66％ and specificity 71.43％ ).The area under curve of MTWA/HR was 0.934(95％ CI0.90 ～0.968 ,P＜0.01 ) ,the optimal cut-off value for screening CAD was 0.12( sensitivity 98.03％ and specificity 82.86％ ).Conclusion:Threshold of HR is lower and the amplitude of MTWA is higher in patients with CAD than those without CAD,MTWA/HR ratio might be a new tool for CAD screening.%目的:探讨在常规运动试验中以时域法微伏级T波电交替(MTWA)筛查冠心病的价值.方法:经冠状动脉(冠脉)造影确诊的冠心病患者152例为冠心病组.对照组为非冠心病者共140例.采用美国GE Marquette Case 800 系统MTWA分析程序以时域法连续分析MTWA及最大MTWA时的心率(HR)为频率阈值,并计算MTWA/HR值.结果:冠心病组时域法MTWA、MTWA/HR值明显高于对照组[(22.04±7.22)μV 比(10.63±6.71)μV,P＜0.01]、(0.21±0.08比0.09±0.06,P＜0.01);频率阈值低于对照组[(107.61±12.06)次/分比(126.23±9.42)次/分,P＜0.01].MTWA筛查冠心病的接收者操作特征曲线下面积为0.908(95%可信区间 0.87～0.95,P＜0.01),最佳切点为11.5 μV(敏感性为97.66%,特异性为71.43%);MTWA/HR值筛查冠心病的接收者操作特征曲线下面积为0.934(95%可信区间0.90～0.97,P＜0.01),最佳切点为0.12(敏感性为98.03%,特异性为82.86%).结论:冠心病患者时域法MTWA的幅度明显高于非冠心病者,频率阈值明显降低,MTWA/HR比值可在运动试验中作为冠心病的筛查指标.