肥厚型心肌病儿童心率变异的改变及其与心脏结构和收缩功能的相关性

Changes of Heart Rate Variability and Its Relativity with Cardiac Size and Systolic Function in Children with Hypertrophic Cardiomyopathy

研究肥厚型心肌病(HCM)患儿的心率变异(HRV)改变及其与心脏结构和收缩功能的相关性。将35例HCM患儿和30例健康儿童分别进行24h心率变异分析,得出SDNN、SDANN、PNN50r、MSSD、LF、HF及LF/HF等指标。行常规超声心动图及组织多普勒检查,取得左室心肌重量指数(LVMI)、左室流出道压力阶差(LVPG)、左室射血分数(LVEF)、短轴缩短率(FS)及室间隔、左心室侧壁、前壁和下壁的二尖瓣瓣环水平的心肌收缩期峰值速度等指标。对两组上述指标进行比较,并分析肥厚型心肌病患儿心率变异性与心脏结构和收缩功能的相关性。结果表明HCM患儿与对照组相比,心率变异指标中SDNN、PNN50r、MSSD、HF均显著降低,SDANN、LF略降低,LF/HF略升高;HF与室间隔的心肌运动峰值速度呈显著的正相关,与左室其它节段的心肌运动峰值速度呈较弱的正相关,与LVMI呈较弱的负相关,其余HRV指标与心脏结构和功能的指标间均无明显相关。HCM患儿有心率变异性改变,表现为自主神经的总体张力减弱,以迷走神经张力减弱为主,交感神经活性相对增强,且HCM患儿迷走神经的张力减弱与左室的收缩功能下降及室壁增厚有一定的相关性。

To investigate the changes of heart rate variability （HRV） and its relativity with cardiac size and systolic function in children with hypertrophic cardiomyopathy （HCM）. Twenty - four- hours HRV parameters including SDNN, SDANN, ,MSSD, PNN50, LF, HF, LF/HF, and left ventricular mass index（ LVMI）, pressure gradient of left ventricular outlet （LVPG）, left ventricular ejection fraction （LVEF）, fractional shorting（FS） and the mean peak velocities of different segments left ventricle from the same level were measured in 35 HCM children and 30 normal controllers using Holter ECG, Color Doppler Echocardiography and quantitative tissue velocity imaging （QTVI） respectively; linear regression was used to analyze the relativity between HRV parameters and clinical parameters. Results showed that SDNN, PNN50, rMSSD and HF were significantly decreased compared with the control, the relativity was only found between HF, LVMI and the mean peak velocities of different segments of left ventricle. Both vagal and sympathetic impairment with a predominance of vagal abnormalities is suggested in children with HCM. Vagal impairment is correlated with abnormality of cardiac systolic function and the hypertrophy of ventricular wall.