Effect Of Pci On Microvolt T-wave Alternans Detected By Dynamic Electrocardiogram In Patients With Acs

ObjectiveTo investigate the changes and significance of microvolt T-wave alternans (MTWA) detected by dynamic electrocardiogram before and after PCI in acute coronary syndrome patients, further to investigate the clinical significance of MTWA in aspects of risk stratification, prognosis and clinical treatment in patients with ACS.Methods39 patients with acute coronary syndrome were selected to take part in the study. All the patients (n=39), were divided into two groups.UA group{group I,n=25 14 male cases,11 female cases, aged 58.1±8.6(45-71)years},including patients with unstable angina pectoris, whose left anterior descending coronary with a stenosis lesion more than 70%, before PCI as group la and groupⅠb that undergone PCI one day later; groupⅡ:Acute ST segment elevation myocardial infarction group.{MI located in anteroseptal,anterior, extensive anterior wall, n=14,8 male cases,6 female cases, aged 63.9±11.0(46-78) years}, Coronary angiography showed left anterior descending artery as infarct-related artery,before PCI as groupⅡa,and groupⅡb after undergone PCI one day later; Control group{ groupⅢ:n=40,22 male cases,18 female cases,age 59.9±8.7 (44-77 years},includes those with negative coronary angiographies or stenoses lesser than 50%. Each group were recorded 24-hour dynamic ECG and the MTWA parameters (Max TWA, TWA at peak HR, TWA at 8AM, Overall TWA) of Channel 1 and Channel 2 with MMA(Modified moving average analy-sis) were analysedResults 1.The MTWA parameters compared among groupsⅠa,Ⅱa,Ⅲbefore PCI: 1)MTWA parameters of groupⅠa were significantly higher than that of groupⅢ(P<0.01 or P<0.05);2) MTWA parameters of groupⅡa were significantly higher than that of groupⅢ(P<0.01);3) MTWA parameters of groupⅡa were significantly higher than that of groupⅠa (P<0.01 or P<0.05)2. The MTWA parameters compared among groupsⅠb,Ⅱb,Ⅲafter PCI:1) MTWA parameters of groupⅡb were significantly higher than that of groupⅠb(P <0.01 or P<0.05);2) MTWA parameters of groupⅡb were significantly higher than that of groupⅢ(P<0.01 or P<0.05);3) MTWA parameters between groupsⅠb andⅢshowed no statistically significant difference(P> 0.05)3.The MTWA parameters compared among groupsⅠa vsⅠb andⅡa vsⅡb before and after PCI:1) MTWA parameters between groupsⅠa andⅠb showed no statistically significant difference (P>0.05).However, the average value of MTWA in groupⅠb less than that of groupⅠa.2) Max TWA of groupⅡb were significantly higher than that of groupⅡa at channel1(mV5) and channel2 ((mV1)(P<0.01).TWA at peak HR,TWA at 8AM and Overall TWA of groupⅡb were significantly less than that of groupⅡa at channel1(mV5) and channel2 ((mV1) (P<0.01 or P<0.05)Conclusion1. The MTWA detected by dynamic electrocardiogram test can be used as one of the methods to risk stratification for patients with acute coronary syndrome;2. Before and after PCI, the patients with acute ST segment elevation myocardial infarction, the Max TWA were instability and reference should be considered. the instability length needed to be studied furtherly;3. Time-domain measurement of MTWA as a simple, reproducible,and non-invasive method, which can indirectly reflex ventricular repolarization inhomogeneities can be used to predict the prognosis of patients with ACS.