Ng Jason, Sundaram Sri, Kadish Alan H, Goldberger Jeffrey J
Division of Cardiology, Feinberg School of Medicine, Northwestern University, Bluhm Cardiovascular Center, Chicago, Illinois 60611, USA.
Am J Physiol Heart Circ Physiol. 2009 Oct;297(4):H1421-8. doi: 10.1152/ajpheart.00217.2009. Epub 2009 Jul 31.
Although frequency-domain analysis of heart rate variability (HRV) has been performed in the setting of exercise and recovery from exercise, the relationship of specific frequency components to sympathetic and parasympathetic inputs has not been validated in this setting. The aim of this study is to evaluate the relationship of frequency components of HRV to sympathetic and parasympathetic modulation in the setting of recovery after exercise using selective autonomic blockade. Normal subjects (n = 27, 17 men, 53 +/- 7 yr old) underwent bicycle stress testing on four separate days. On day 1, a baseline study without autonomic blockade was performed. On days 2 through 4, either beta-adrenergic, parasympathetic, or double blockade was administered during exercise and completed 3 min before recovery. Continuous ECG was recorded for 5 min starting from the end of exercise. Time- and frequency-domain measures of HRV were computed for each of the five 1-min segments of RR intervals. Parasympathetic blockade significantly decreased all the HRV measures compared with baseline (P < 0.02 for all). Root mean square of successive differences of RR intervals (rMSSD) was increased by beta-adrenergic blockade (P < 0.0002). All the HRV measures except rMSSD showed increases with time after the first minute of recovery. The low frequency-to-high frequency ratio did not respond to autonomic blockade or to recovery time, consistent with the expected changes in sympathovagal influence. Root mean square (detrended SD) and rMSSD were highly correlated with the square root of the total power (r = 0.96) and high-frequency power (r = 0.95), respectively. Although there are marked reductions in the frequency-domain measures in recovery versus rest, the fluctuations in the low- and high-frequency bands respond to autonomic blockade in the expected fashion. Time-domain measures of HRV were highly correlated with frequency-domain measures and therefore provide a computationally more efficient assessment of autonomic influences during recovery from exercise that is less susceptible to anomalies of frequency-domain analysis.
尽管已在运动及运动恢复过程中对心率变异性（HRV）进行了频域分析，但在这种情况下，特定频率成分与交感神经和副交感神经输入之间的关系尚未得到验证。本研究的目的是使用选择性自主神经阻滞来评估运动后恢复过程中HRV频率成分与交感神经和副交感神经调制之间的关系。正常受试者（n = 27，17名男性，53±7岁）在四个不同的日子里进行了自行车压力测试。在第1天，进行了无自主神经阻滞的基线研究。在第2天至第4天，在运动期间给予β-肾上腺素能、副交感神经或双重阻滞，并在恢复前3分钟完成。从运动结束开始连续记录5分钟的心电图。对RR间期的五个1分钟时间段中的每一个计算HRV的时域和频域测量值。与基线相比，副交感神经阻滞显著降低了所有HRV测量值（所有P < 0.02）。RR间期连续差值的均方根（rMSSD）因β-肾上腺素能阻滞而增加（P < 0.0002）。除rMSSD外，所有HRV测量值在恢复的第一分钟后均随时间增加。低频与高频比值对自主神经阻滞或恢复时间无反应，这与交感迷走神经影响的预期变化一致。均方根（去趋势标准差）和rMSSD分别与总功率的平方根（r = 0.96）和高频功率（r = 0.95）高度相关。尽管与休息相比，恢复过程中的频域测量值有明显降低，但低频和高频带的波动以预期方式对自主神经阻滞作出反应。HRV的时域测量值与频域测量值高度相关，因此在运动恢复过程中提供了一种计算效率更高的自主神经影响评估方法，且不易受频域分析异常的影响。
