充血性心力衰竭患者心率变异性分析

Analysis of heart rate variability in chronic congestive heart failure

心率变异性（ＨＲＶ）分析是反映支配心脏自主神经活性的一项无创性指标。我们通过ＨＲＶ时域和频域分析法，研究５１例正常人、６０例不同病因致慢性充血性心力衰竭患者的心率变异特性。结果表明：慢性充血性心力衰竭患者的２４小时ＲＲ间期标准差（ＳＤＮＮ）和ＨＲＶ指数，明显低于正常人。频域分析显示正常人心率变异功率谱密度（ＰＳＤ），日间以低频成分占优势，夜间睡眠时则高频成分占主导，低频成分昼夜变化不明显。慢性充血性心力衰竭患者，心率变异性ＰＳＤ与正常人相比，显示低频和高频成分均明显降低，且高频成分的下降尤为显著，这表明慢性充血性心力衰竭患者支配心脏的迷走和交感神经均受损，且以迷走神经受损更为严重。这可能意味着患者日后发生心脏猝死的危险性增加。

Abstract Heart rate variability (HRV) has been proposed as a noninvasive means to monitor the autonomic nervous activity of the heart. In the present study HRV of 51normal subjects and 60 patients with chronic congestive heart failure (CHF) of different etiology was analyzed using frequency domain measures (heart rate power spectrum density , HRPSD) as well as time domain analysis (mean RR interval standard deviation, SD and heart rate variability index, HRVI) from 24-hour Holter tapes. Normal subjects had significantly greater HRV than patients with chronic CHF (SD 51. 90± 11. 4vs 34. 54 ± 10. 5 ms, respectively, P<0. 001 ; HRVI21. 89 ± 8. 9 vs 37. 98 ± 11. 3, respectively, P<0. 001). PSD analysis showed that in normals low-fre-quency was more pronounced during the day while highfrequency most evident at night. However, the low-fre-quency component remained almost unchanged during 24-hours. Spectral analysis in both groups showed a low frequency and a high frequency peak , but the magnitude was greatly reduced in chronic CHF patients with depressed ejection fraction (LVEF<30 % ) , especially the high frequency component comparing with the normals (total variability 758. 7± 496. 9 vs 1990. 8±993. 8 ms2/Hz, respectively , P<0. 001 ). The results suggest severe impairment of autonomic activity of the heart in chronic CHF and imply increased risk of subsequent sudden cardiac death.