扩张型心肌病患者心率减速力的临床研究

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

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。

Objective： To study the change of heart rate deceleration capacity （DC） in patients with dilated cardiomy- opathy （DCM） and its relationship with left ventricular ejection fraction （LVEF） and heart rate variability （HRV）. Meth- ods： 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,） and high frequency power（ HFn ） 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 be- tween DC and LVEF, time domain indices - SDNN, RMSSD as well as frequency domain indices HFn of HRV parameters were observed （P 〈 0.01）. Conclusions： DC is depressed in patients with DCM. DC is a new noninvasive method to as- sess autonomic nerve function and also a risk prediction of patients with DCM.