Lombardi F, Sandrone G, Mortara A, La Rovere M T, Colombo E, Guzzetti S, Malliani A
Istituto Ricerche Cardiovascolari, Consiglio Nazionale delle Ricerche, Pavia, Italy.
Am Heart J. 1992 Jun;123(6):1521-9. doi: 10.1016/0002-8703(92)90804-5.
The circadian variations of spectral indices of heart rate variability were analyzed in 20 patients 4 weeks after a first and uncomplicated myocardial infarction (MI) and in 20 control subjects. R-R interval and variance showed a characteristic day-night pattern with a significant reduction of the latter parameter in patients after MI (10,967 +/- 1109 msec2 vs 16,860 +/- 2132 msec2). Control subjects were characterized by a predominance of low-frequency (approximately 0.1 Hz) component during the day and of high-frequency (approximately 0.25 Hz) component during the night, which reflected the expected 24-hour pattern of variation of sympatho-vagal balance. A 24-hour elevation (64 +/- 3 normalized units [nu] vs 56 +/- 2 nu; p less than 0.05) of the low-frequency component and a smaller (23 +/- 2 nu vs 32 +/- 2 nu; p less than 0.05) high-frequency component during the night differentiated patients after MI from subjects. The difference between the two groups was even more evident when the 24-hour sympatho-vagal balance was assessed with the low frequency/high frequency ratio. Thus spectral analysis of heart rate variability indicates that in patients after MI there is an alteration of neural control mechanisms as indicated by the presence of signs of sympathetic activation and by the attenuation of the nocturnal increase in vagal tone.
对20例首次发生且病情不复杂的心肌梗死（MI）患者在发病4周后以及20名对照者的心率变异性频谱指标的昼夜变化进行了分析。R-R间期和方差呈现出特征性的昼夜模式，MI后患者的后一参数显著降低（10,967±1109毫秒²对16,860±2132毫秒²）。对照者的特征是白天低频（约0.1赫兹）成分占优势，夜间高频（约0.25赫兹）成分占优势，这反映了交感-迷走神经平衡预期的24小时变化模式。MI后患者夜间低频成分升高（64±3标准化单位[nu]对56±2 nu；p<0.05），高频成分降低（23±2 nu对32±2 nu；p<0.05），这将MI后患者与对照者区分开来。当用低频/高频比值评估24小时交感-迷走神经平衡时，两组之间的差异更为明显。因此，心率变异性频谱分析表明，MI后患者存在神经控制机制的改变，表现为交感激活迹象的存在以及夜间迷走神经张力增加的减弱。
