缺血与非缺血性心脏病微伏级T波电交替检测分析

Detection and analysis of microvolt T-wave alternans in patients with ischemic heart disease and non ischemic heart disease

目的 探讨扩张型心肌病与冠心病患者微伏级T波电交替（MTWA）的发生情况及其与室性心律失常和心脏性猝死（SCD）的关系.方法 选取2010年3月至2012年3月明确诊断的冠心病和扩张型心肌病（心肌病）各30例,健康对照组45例,用Cambridge Heart.HeartwaveTM system心脏诊断系统,频谱法检测MTWA,将MTWA阳性与不确定性合并称为非阴性.以持续性室速、室颤及猝死为终点事件,观察MTWA非阴性结果对事件的预测价值.采用SPSS l3.0统计软件分析数据,两独立样本间比较采用秩和检验,计数资料的比较用χ2检验.结果 ①心肌病组、冠心病组MTWA阳性率高于对照组（χ2=29.525,P＜0.01;χ2=10.185,P＜0.01）、不确定性高于对照组（χ2=4.571,P＜0.01; χ2=4.571,P＜0.01）,阴性率低于对照组（χ2=38.942,P＜0.01;χ2 =36.000,P＜0.01）.心肌病组MTWA非阴性为76.6％（23/30）,高于对照组（6.6％,3/45）（χ2=38.942,P＜0.01）;冠心病组非阴性为73.33％（22/30）,高于对照组（χ2=36.000,P ＜0.01）,心肌病组与冠心病组比较MTWA非阴性差异无统计学意义（χ2=0.089,P ＞0.05）.②心肌病组与冠心病组静息时交替压（Valt）无差异（P＞0.05）;运动后Vm、X、Y、Z导联心肌病组Valt大于冠心病组[分别为2.5 （2.00～3.35） μV与2.00 （2.00 ～2.60） μV,Z=-2.189;2.00（2.00～3.00） μV与2.00 （1.90～2.00） μV,Z=-1.788;2.00 （2.00～3.10） μV与2.00（1.98～2.25） μV,Z=-2.141;2.20（2.00～3.00） μV与2.00（1.90～2.25） μV,Z=-1.982;P均＜0.05].③MTWA非阴性预测事件发生的敏感度77.48％,特异度25.49％.结论 MTWA阳性与不确定性对心肌病和冠心病室性心律失常及猝死的发生有一定预测价值.

Objective To investigate the occurrence of Microvoh T-wave alternans in patients with dilated cardiomyopathy（DCM） and coronary heart disease （CHD）, explore the relationship between MTWA and ventricular arrhythmias and sudden cardiac death （SCD）. Methods The MTWA analysis was performed in 30 DCM and 30 CHD and 45 healthy subjects with spectral method using Cambridge Heart. HearwaveTM system. The non-negative of MTWA was defined as positive and indeterminate. The endpoints were defined as sustained ventricular taehycardia, ventricular fibrillation or SCD. The predictive value of non-negative of MTWA was assessed. Results （1）The positive rate of MTWA in DCM or in CHD was higher than that of healthy subjects（χ2 = 29. 525 ,P 〈0.01 ; χ2 = 10. 185 ,P 〈0.01 ）. The indeterminate was higher too （χ2 = 4.571, P 〈 0.01 ; χ2 = 4. 571, P 〈 0.01 ） ;The negative rate was lower （χ2 = 38. 942, P 〈 0.01 ; χ2 = 36. 000, P 〈 0.01 ）. The non-negative of MTWA in DCM was 76.67 % （ 23/30 ） and was higher than that of healthy subjects （ 6.67% ,3/45 ） （χ2 = 38. 942, P 〈 0.01 ）, in CHD was 73.33% （22/30） and was higher than that of healthy subjects （χ2 = 36. 000 ,P 〈 0.01 ）. The non-negative was no different between the DCM group and the CHD group（ χ2 =0. 089,P 〉 0.05）. （2）Both DCM group and CHD group, the alternating voltage（Valt） during exercise was significantly higher than the rest. At rest, Vah was no difference between two groups （ P 〉 0.05 ）. During exercise, Valt in DCM group was higher than in CHD group at all orthogonal leadsrespectively 2.5（2.00 -3.35）μV vs 2.00 （2.00 -26.0） μV, Z = -2. 189; 2.00（2.00 -3.00）μV vs 2.00 （1.90-2.00） μV, Z= -1.788;2.00（2.00 -3.10）μV vs2.00（1.98-2.25）μV, Z= -2. 141; 2.20 （2.00-3.00） μV vs 2.00 （1.90-2.25） μV, Z= -1.982; all P〈0.05.（3）The sensitivity of non-negative of MTWA concerning arrhythmie event amounted to 77.48%, the specificity to 25.49% , respectively. Conclusion The non-negative of MTWA in patients with DCM and the patients with CHD is higher than that in healthy subjects. The non-negative of MTWA seems to identify patients with DCM and CAD who are an increased risk of ventrieular taehyarrhythmias and SCD.