Miyamoto Shoichi, Fujita Masatoshi, Tambara Keiichi, Sekiguchi Hiroyuki, Eiho Shigeru, Hasegawa Koji, Tamaki Shun-ichi
Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Int J Cardiol. 2004 Feb;93(2-3):247-52. doi: 10.1016/S0167-5273(03)00190-6.
It remains unclear whether circadian variation (CV) of cardiac autonomic nervous activity (CANA) is preserved in patients with chronic heart failure (CHF) as in healthy subjects. We have demonstrated that CANA in CHF patients is largely affected by patient recumbent position.
We studied eight mild to moderate CHF patients and eight age, sex-matched healthy subjects. Each subject underwent 24-h ambulatory ECG monitoring. One channel was used to record the CM5 lead, and another to record the signal of patient position from a newly developed, small-sized detector. By using spectral analysis of heart rate variability, frequency-domain measures were calculated. Normalized high-frequency (HF: 0.15-0.40 Hz) power was used as an index of vagal activity and the low frequency (LF: 0.04-0.15 Hz)/HF power ratio was used as an index of sympathovagal balance. These indexes in the same recumbent position were compared between night (2:00-4:00 a.m.) and morning (6:00-8:00 a.m.).
In healthy subjects, a definite CV of CANA was observed in each recumbent position. In patients with CHF, in each position, normalized HF power was lower in the morning than at night, whereas LF/HF was higher in the morning than at night. Thus, CANA in CHF patients is influenced not only by patient position but also by the time of day.
CV of CANA in mild to moderate CHF patients is well preserved when taking patient position into consideration.
慢性心力衰竭（CHF）患者心脏自主神经活动（CANA）的昼夜节律变化（CV）是否如健康受试者一样得以保留尚不清楚。我们已经证明，CHF患者的CANA在很大程度上受患者卧位的影响。
我们研究了8例轻至中度CHF患者和8例年龄、性别匹配的健康受试者。每位受试者均接受24小时动态心电图监测。一个通道用于记录CM5导联，另一个通道用于记录来自新开发的小型探测器的患者体位信号。通过心率变异性频谱分析计算频域指标。将归一化高频（HF：0.15 - 0.40Hz）功率用作迷走神经活动指标，低频（LF：0.04 - 0.15Hz）/HF功率比用作交感神经 - 迷走神经平衡指标。比较同一卧位下夜间（凌晨2:00 - 4:00）和早晨（上午6:00 - 8:00）的这些指标。
在健康受试者中，每个卧位均观察到明确的CANA昼夜节律变化。在CHF患者中，每个体位下，早晨的归一化HF功率均低于夜间，而早晨的LF/HF高于夜间。因此，CHF患者的CANA不仅受患者体位影响，还受一天中时间的影响。
考虑患者体位时，轻至中度CHF患者CANA的昼夜节律变化得到很好的保留。
