肥厚性心肌病合并心房颤动患者的心率变异性特点

Characteristics of heart rate variability in patients with hypertrophic cardiomyopathy complicated with atrial fibrillation

目的探讨肥厚性心肌病(HCM)合并心房颤动(AF)患者的心率变异性(HRV)特征。方法选择HCM患者98例,其中合并AF者(AF组)20例,不合并AF组(对照组)78例,另选取98例健康志愿者为正常组,均行心电图、心脏彩超,并采用24h动态心电图方法分析3组间HRV的时域指标[全部正常窦性心搏R-R间期标准差(SDNN)、连续5 min正常R-R间期标准差的均值(SDNNindex)、全程相邻R-R间期之差的均方根值(rMSSD)、相邻的R-R间期之差大于50ms的心搏数除以总的R-R间期的百分率(pNN50)]、频域指标[低频段(LF)、高频段(HF)、LF/HF]。再将AF组分成无症状AF组14例与有症状AF组6例,比较两组的HRV指标。结果与对照组以及正常组比较,AF组SDNN、SDNNindex、rMSSD、pNN50、LF、HF升高(均P<0.05);有症状AF组SDNN、SDNNindex、rMSSD较无症状AF组升高(均P<0.05)。与正常组比较,AF组左房内径升高而左室射血分数降低(均P<0.05)。正常组与对照组间以上指标比较差异均无统计学意义(均P>0.05)。结论 HCM合并AF患者存在自主神经功能紊乱、迷走神经活性增高,而这一特点在有症状的AF患者中更显著。

Objective To explore the characteristics of heart rate variability（HRV） in patients with hypertrophic cardiomyopathy（HCM） complicated with atrial fibrillation（AF）. Methods A total of 98 patients with HCM were enrolled,including 20 patients complicated with AF（AF group） and 78 patients without AF（control group）. A total of 98 healthy volunteers were enrolled as normal group. All of the subjects underwent electrocardiography and color Doppler ultrasonography. HRV of the three groups was analyzed using 24-hour dynamic electrocardiogram. The indices of HRV consisted of the time domain indices[standard deviation of all normal sinus RR intervals（SDNN）,mean of standard deviation of normal sinus RR intervals for all 5-minute segments（SDNNindex）,root mean square of successive differences in normal to normal RR intervals（rMSSD）,and percentage of normal RR-intervals with duration more than 50 ms different from the previous normal RR-interval（pNN50） ] and frequency domain indices[low frequency（LF）,high frequency（HF） and LF/HF） ]. The AF group was divided into asymptomatic AF group（n = 14） and symptomatic AF group（n = 6） and the indices of HRV were compared between the two groups. Results Compared with the control group and the normal group,SDNN,SDNNindex,rMSSD,pNN50,LF and HF were significantly higher in the AF group（all P〈0. 05）. SDNN,SDNNindex and rMSSD in the symptomatic AF group were significantly higher than those in the asymptomatic AF group（all P〈0. 05）. Left arterial dimension increased and left ventricular ejection fraction decreased in the AF group compared to those in the normal group（all P〈0. 05）. There were no significant differences in all indices above between the normal group and the control group（P〉0. 05）. Conclusion Autonomic nerve dysfunction and increased vagal activity are found in patients with HCM complicated with AF,and it is more obvious in patients with symptomatic AF.