中文摘要：

目的探索慢性心力衰竭患者QT问期频率依赖性与室性心律失常的关系。方法选31例慢性心力衰竭患者有效病例资料。检测左心室舒张末期内径（LVEDD）、左心室射血分数（LVEF）、QT间期离散度（QTd）、心率变异性（HRV）、QT／RR相关直线的斜率、24h室性早搏（VPB）和非持续性室性心动过速（NSVT）的次数。比较有NSVT和无NSVT患者上述指标的差别，研究上述指标与NSVT的相关性。结果31例心力衰竭患者中，有17例动态心电图记录到NSVT。有NSVT与无NS—VT的患者比较，VPB次数[（5631．2±7218．0）对（285．9±371．7），P〈0．05]，QTe／RR斜率[（0．210±0．049）对（0．161±0．058），P〈0．05]和QTp／RR斜率[（0．195±0．046）对（0．151±0．041），P〈0．05]的差异有统计学意义。在全部31例患者中，QTd（r=0．414）、VPB次数（r=0．768）、QTe／RR斜率（r=0．380）、QTp／RR斜率（r=0．433）和NSVT有显著的相关性（P〈0．05）。结论QT间期频率依赖性是反映QT间期动态变化的指标，慢性心力衰竭患者的QT／RR斜率与室性心律失常有较好的相关性，在心脏性猝死的风险评估中有一定价值。

英文摘要：

Objective To investigate the relationship between QT interval rate dependence and ventricular arrhythmias in patients with chronic heart failure. Methods Thirty-one patients with chronic heart failure were enrolled in this study and investigation included history collection, clinical examination, echocardiography, electrocardiogram and 24 h ambulatory electrocardiogram. Following indexes were determined, left ventricular end diastolic dimension （ LVEDD ） , left ventricular ejection fraction （ LVEF ） , QT dispersion （ QTd ） , SDNN, the slope of QT/RR plots of the linear regression, ventrieular premature beats （VPB）and non-sustained ventricular tachycardia（ NSVT）. All above indexes were compared between patients with and without NSVT,The correlation factor between QT/RR slope and NSVT was calculated. Results In 31 patients with chronic heart failure,there were 17 patients with NSVT in their 24 h hoher recording. The frequency of VPB （5631.2 ± 7218.0 vs 285.9 ±371.7, P 〈 0. 05 ）, QTe/RR slope （0. 210 ± 0. 049 vs 0. 161 ±0. 058, P 〈 0. 05 ） and QTp/ RR slope（0. 195 ± 0. 046 vs 0. 151 ± 0. 041, P 〈 0.05 ）were significantly higher in patients with NSVT than those without. In all patients, QTd （ r = 0. 414, P 〈 0.05 ）, VPB （ r = 0. 768, P 〈 0. 05 ）, QTe/RR slope （ r = 0. 380, P 〈 0. 05 ） and QTp/RR slope （ r = 0. 433, P 〈 0. 05 ） highly correlated to the frequency of NSVT. Conclusion QT interval rate dependence represents the dynamic QT variance over time. QT/RR slope correlates to the ventricular arrhythmia tightly, and is valuable for the risk stratification of sudden cardiac death in chronic heart failure.