微伏级T波电交替及窦性心律震荡对扩张型心肌病患者猝死的预测价值

Prognostic significance of microvolt T-wave alternans and heart rate turbulence for sudden cardiac death in patients with dilated cardiomyopathy

目的评价窦性心律震荡（HRT）和微伏级T波电交替（m TWA）对扩张型心肌病患者猝死的预测价值。方法选取扩张型心肌病患者87例,健康体检者60例,根据24小时动态心电图（Holter）记录资料,计算HRT的两个参数震荡初始（TO）和震荡斜率（TS）,采用时域法检测m TWA,比较两组的差别;同时对扩张型心肌病患者随访2年,主要终点为心源性猝死,次要终点为全因死亡及非猝死性心血管死亡,评估死亡组与存活组,死亡各亚组之间HRT及m TWA的差异性。结果死亡组m TWA及HRT2明显升高。其中心源性猝死亚组m TWAmax和HRT2异常较非猝死组明显升高;而06：00 m TWA（WF1/8）则以非心源性猝死组为高。COX回归分析发现,LVEDD、HRT2、m TWA（06：00 AM）为最有意义的独立致死因子;LVEDD、HRT2、m TWA（100次/分）和室性早搏数量为心源性猝死的危险因素。异常TO/TS联合m TWA（100次/分）大于64.5 mc V则显著增加全因死亡率[RR,28.5（95%CI 4.2-138.5）,P〈0.001]及心源性猝死风险[RR,62.5（95%CI 6.2-516.5）,P〈0.001]。当三个危险因素均出现时其增加全因死亡率及心源性猝死风险居中。LVEDD大于60 mm和HRT2能更好地预测全因死亡率及心源性猝死风险。结论当患者HRT和m TWA异常时总病死率及心源性猝死风险明显增加。

Objective To evaluate the predictive value of heart rate turbulence（ HRT） and microvolt T-wave alternans（ m TWA） for sudden cardiac death（ SCD） in patients with dilated cardiomyopathy. Methods 87 patients with dilated cardiomyopathy and 60 healthy people were selected. Then,data were recorded,turbulence onset（ TO） and turbulence slope（ TS） of HRT were calculated according to 24 h ambulatory electrocardiogram monitoring（ Holter）. m TWA was tested by time domain method and compared between groups. Patients with dilated cardiomyopathy were given follow-up visit for 2 years,primary endpoint was SCD,secondary endpoint was all-cause death and non SCD. In addition,HRT and m TWA of death group,survival group and each death subgroup was evaluated. Results m TWA and HRT2 of the death group significantly increased,among which abnormal m TWA and HRT2 of SCD subgroup increased more significantly than those of the non SCD subgroup. And non SCD group had highest m TWA（ WF1 /8） at 6： 00 AM. Cox-regression analysis showed that LVEDD,HRT2 and m TWA（ 06： 00 AM） were the most significant independent lethal factors. And risk factors for SCD were LVEDD,HRT,m TWA（ 100 bpm） and the number of premature ventricular beats. Combination of abnormal TO / TS and m TWA（ 100bpm） 64. 5 mc V significantly increased rate of all-cause death [RR,28. 5（ 95% CI 4. 2 - 138. 5）,P〈0. 001] and SCD risk [RR,62. 5（ 95% CI 6. 2 - 516. 5）,P〈0. 001]. In addition,when the above-mentioned risk factors all appeared,rate of all-cause death and SCD risk were at intermediate level. Furthermore,LVEDD 60 mm and HRT2 could better predict the rate of all-cause death and SCD risk. Conclusion Overall mortality and SCD risk significantly increase when HRT and m TWA of patients are abnormal.