扩张性心肌病恶性心律失常与心室复极变异性的关系

Relationship between fatal arrhythmia and variability of ventricular repolarization in dilated cardiomyopathy

目的探讨扩张性心肌病(DCM)患者恶性心律失常与心室复极变异性的关系。方法47例扩张性心肌病患者按是否发生恶性心律失常分为两组,进行24h动态心电图(Holter)检测,计算机自动测量连续的正常窦性心搏的QT间期、RR间期,并分别计算24h标准化QT变异度(QTVnor)、标准化心率变异度(HRVnor)和QT变异度指数(QTVI)。比较两组QTVnor、HRVnor和QTVI,并对QTVnor和HRVnor进行相关性分析。结果DCM患者恶性心律失常组比对照组24hQTVnor和QTVI增大(1.3±1.0vs0.8±0.5,P<0.05;0.11±0.52vs-0.48±0.28,P<0.001),QTVnor和HRVnor中度相关(研究组r=0.41,P<0.05;对照组r=0.55,P<0.05)。结论扩张性心肌病患者QTV受HRV影响,消除心率变异影响后,发生恶性心律失常的DCM患者心室自身复极变异性增大。标准化QT变异度和QT变异度指数是测定心室复极变异性、预测恶性心律失常有用的新指标。

Objective To study the relationship between fatal arrhythmia and variability of ventricular repolarization in dilated cardiomyopathy(DCM). Methods Forty-seven patients with DCM were examined by 24-h Holter monitoring.QT interval and RR interval were measured by computer.The normalized QT variability (QTVnor),the normalized HRV variability (HRVnor) and QT variability index (QTVI) were determined,the data were calculated for each subject as logarithms of the radio of normalized QT variance to heart variance by the squared mean. Results QTVnor and QTVI in study subjects in 24 hours was higher than in the control group (1.3±1.0 to 0.8±0.5,P<0.05; 0.11±0.52 to -0.48±0.28, P<0.01),QTVnor in two group was related with HRVnor (rstudy=0.41,P<0.05;rcontrol=0.55,P<0.05). Conclusion QTV in DCM correlated with HRV;QTVnor and QTVI in DCM with arrhythmia risk were higher, which suggested a greater repolarization variability without HRV.It is a new useful prediction index.