扩张型心肌病患儿心率变异改变及其与心脏大小和功能的关系

Relationship between the change of heart rate variabilityand cardiac size and function in childrenwith dilated cardiomyopathy

目的探讨扩张型心肌病(DCM)患儿心率变异(HRV)改变及其与心脏大小和收缩舒张功能的相关性。方法对30例DCM患儿(DCM组)和30例健康儿童(对照组)行24h动态心电图检查,并记录HRV指标(SDNN、SDANN、SDNN index、RM SSD、PNN50、TP、LF、HF、LF/HF);同时行超声心动图检查,测量左室舒张末期内径(LVED)、左房舒张末期内径(LAED)、左心室射血分数(LVEF)、短轴缩短率(LVFS)和二尖瓣E/A峰比值,并分析这两类指标之间的相关性。结果DCM组HRV指标除LF/HF较对照组升高外,其余均较对照组明显降低;SDNN与LAED、LVEF、LVFS和E/A呈中度相关,其余指标与心脏大小和收缩舒张功能无明显的相关性。结论DCM患儿存在明显的自主神经平衡失调,主要表现为迷走神经张力减退,交感神经的相对激活;HRV与心脏大小和收缩舒张功能指标相对独立,其作为一无创性检测指标,可从一个侧面反映DCM患儿的预后,将它们结合起来能更好地指导临床。

Objective： To investigate the changes of heart rate variability （HRV） and its relativity with cardiac size and function in children with dilated cardiomyopathy （DCM）. Methods： 24h HRV parameters including SDNN, SDANN, SDNNindex, RMSSD, PNN50, TP, LF, HF, LF/HF, and end diastolic diameter of left ventricle （LVED）, end diastolic diameter of left atrial （LAED）, left ventricular ejection fraction （LVEF）, fractional shorting （LVFS）, E/A were measured in 30 DCM children and 30 normal controls using Holter ECG and color doppler echocardiography respectively; Linear regression was used to analyze the relativity between HRV parameters and clinical parameters. Results ： HRV in DCM group was significantly decreased, the relativity was only found between SDNN and LAED, LVEF, LVFS, E/A. Conclusions： The disequilibium of autonomic nerve system and the decrease of HRV exists in children with DCM. HRV and the index of cardiac systolic function are independent, the combination of them may be helpful to clinical work.