扩张型心肌病患者心率减速力的临床研究

目的:研究心率减速力(DC)在扩张型心肌病(DCM)患者中的变化以及与左室射血分数(LVEF)、心率变异性(HRV)之间的关系。方法:32例DCM患者和34例正常人接受24h动态心电图检查和超声心动图检查,计算机分别测定2组患者的DC、LVEF及HRV时域指标(SDNN,RMSSD)与标化的频域指标(LFn、HFn);比较2组患者的DC、LVEF、SDNN,RMSSD、LFn及HFn,并研究DCM患者的DC与LVEF及HRV各指标之间的关系。结果:DCM患者的DC值明显小于正常对照组(3.3±2.3msvs6.9±1.4ms,P<0.01),其异常DC的发生率高达89.7%,明显高于正常对照组(P<0.01);DCM组患者的DC与LVEF、SDNN、RMSSD、LFn及HFn之间呈明显的正相关关系。结论:DCM患者的DC值明显降低,DC是一项可用以定量评估DCM患者自主神经张力并筛选高危患者的新的可靠指标。

Clinical study of heart rate deceleration capacity in patients with dilated cardiomyopathy

Objective: To study the change of heart rate deceleration capacity (DC) in patients with dilated cardiomyopathy (DCM) and its relationship with left ventricular ejection fraction (LVEF) and heart rate variability (HRV) . Methods: Using 24h Holter recordings and Echocardiography,DC,LVEF,time and frequency domain parameters of HRV were measured by computer in 32 patients with DCM and 34 healthy adults (control group) . DC,LEVF,standard deviation of normal R-R intervals (SDNN) ,squares of differences between adjacent NN intervals (RMSSD) ,low frequency power (LF n) and high frequency power(HF n) were compared between the two groups,the relationship between DC,LVEF and HRV were studied in patient with DCM. Results: The median value of DC in the patients with DCM was significantly lower than that in control group(3. 28 ± 2. 30 ms vs 6. 91 ± 1. 43 ms,P < 0. 01) . Incidence of abnormal DC in the DCM group was 89. 7% ,which was significantly higher than that in the control group (P < 0. 01) . Significant positive correlation between DC and LVEF,time domain indices-SDNN,RMSSD as well as frequency domain indices HF n of HRV parameters were observed (P < 0. 01) . Conclusions: DC is depressed in patients with DCM. DC is a new noninvasive method to assess autonomic nerve function and also a risk prediction of patients with DCM.