QT变异性对急性心肌梗死后恶性室性心律失常预测价值的研究

Value of QT variability for predicting patients with acute myocardial infarction at risk for malignant ventricular arrhythmias

目的评价QT间期变异性对急性心肌梗死后恶性室性心律失常的预测价值。方法入选我院CCU病房急性心肌梗死患者108例(男性80例,女性28例),均于入院当日(急性期)、出院前日(恢复期),使用心电图仪记录300个RR间期。两次样本采用“四点法”借助放大镜逐点测量,所测数值全部导入计算机,经Excel函数分析系统处理,取得SDNN、QTm、QTSD、QTV、QTVI、B的参数。比较室性心律失常Lown分级与上述参数变化的关系。从而评定该指标对恶性心律失常的预测能力。结果急性期组与恢复期组的比较:QTm、QTV、QTVI、B分别为(369±54ms vs423±49ms;0.020±0.008vs0.11±0.004;-0.19±0.06vs-0.40±0.08,p<0.05;1.11±0.52vs0.37±0.09,p=0.02)有显著性差异。SDNN(24.8±7ms vs25.8±8ms,p>0.05)无显著性差异,QTSD(7.7±2.5ms vs45±1.3ms p=0.05)有弱的相关性。恢复期组观察到的室性心律失常等级、数量也明显降低。急性期室性心律失常Lown0-Ⅱ级组与LownⅢ-Ⅴ级组观察指标对比分析QTVI(-0.29±0.07vs-0.13±0.05,p=0.038),B(0.78±0.18vs1.64±0.4,p=0.007)两者均有显著性差异。结论短程QT间期变异性可作为急性心肌梗死后恶性室性心律失常的预测指标,其中QTVI、B两项参数敏感性最高。

Objective To evaluate the value of QT interval variability in predicting malignant ventricular arrhythmia after acute myocardial infarction. Methods QT interval variability was calculated from a one-lead electrocardiogram in 108 patients of acute myocardial infarction admitted in coronary care unit, each was measured twice, one in admission （acute stage）, the other prior to discharge （stable stage）. The parameters of SDNN, QTm ,QTSD ,QTV ,QTVI ,B were analyzed, The Changes of these parameters were also compared among various Lown grades of ventricular arrhythmias. Thus the predicting value of QT interval variability were assessed. Resuits Parameters between acute and stable groups were as follow respectively： QTm 369±54ms vs 423±49ms, QTV 0.020±0.008 vs 0.11 ±0.004, QTVI -0.19±0.06 vs -0.40±0.08 （ p 〈0.05 ）, B 1.11 ±0.52 vs 0.37±0.09 （p = 0.02） ,SDNN 24.8±7ms vs 25.8±8ms （p〉0.05）,also QTSD 7.7±2.5ms vs 45±1.3ms（p=0.05）. In the stable group, the grade and quantity of ventricular arrhythmias were obviously lower. During acute stage, ventricular arrhythmias of Lown0-Ⅱ and LownⅢ-Ⅴ different with QTVI （-0.29±0.07 vs -0.13±0.05）（p=0.038）,B （0.78±0.18 vs 1.64±0.4）（p=0.007）, changes of the both parameters have high degree of significance. Conclusions Short-range QT variability can be a marker of electrical disease in the ventricle and may be associated with enhanced risk of life-threatening arrhythmias following acute myocardial infarction, especially the more sensitive parameters QTVI and B.