Zinkovska S M, Rodriguez E K, Kirby D A
Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
Am J Physiol. 1996 Feb;270(2 Pt 2):H723-9. doi: 10.1152/ajpheart.1996.270.2.H723.
Changes in autonomic tone in the vasculature during sleep may have important implications for silent ischemia and sudden cardiac death. Few models exist in which both cardiac output and coronary blood flow are continuously measured during natural sleep and autonomic mechanisms are assessed. Catheters were chronically implanted in the aorta to measure mean arterial pressure (MAP), and flow probes were placed on the ascending aorta and the circumflex coronary artery of 18 pigs. Electrodes determined sleep stage as either non-rapid eye movement (NREM) or rapid eye movement (REM) sleep. The MAP was 73 +/- 3 mmHg in the quiet awake state, did not change in NREM, and decreased to 64 +/- 2 mmHg in REM sleep (P < 0.05). In NREM sleep, heart rate did not change from awake state values of 136 +/- 8 beats/min but increased by 5 beats/min in REM sleep (P < 0.05). Coronary vascular resistance decreased from awake state values of 2.7 +/- 0.2 to 2.2 +/- 0.2 mmHg.ml-1.min in REM (P < 0.05); total peripheral resistance decreased from awake values of 0.061 +/- 0.004 mmHg.ml-1.min to 0.050 +/- 0.003 in REM sleep (P < 0.05). Those changes appear to have been mediated primarily by reduction of alpha-adrenergic activity. Spectral analysis of heart rate suggests that power in the high-frequency range (a presumed indicator of parasympathetic tone) was lower in REM sleep than NREM sleep.
睡眠期间血管系统自主神经张力的变化可能对无症状性缺血和心源性猝死具有重要意义。目前很少有模型能够在自然睡眠期间连续测量心输出量和冠状动脉血流量，并评估自主神经机制。将导管长期植入主动脉以测量平均动脉压（MAP），并在18头猪的升主动脉和左旋冠状动脉上放置流量探头。电极确定睡眠阶段为非快速眼动（NREM）睡眠或快速眼动（REM）睡眠。安静清醒状态下MAP为73±3 mmHg，NREM睡眠时不变，REM睡眠时降至64±2 mmHg（P<0.05）。在NREM睡眠中，心率与清醒状态下的136±8次/分钟相比没有变化，但在REM睡眠中增加了5次/分钟（P<0.05）。冠状动脉血管阻力从清醒状态下的2.7±0.2降至REM睡眠时的2.2±0.2 mmHg·ml-1·min（P<0.05）；总外周阻力从清醒时的0.061±0.004 mmHg·ml-1·min降至REM睡眠时的0.050±0.003（P<0.05）。这些变化似乎主要是由α-肾上腺素能活性降低介导的。心率的频谱分析表明，高频范围内的功率（副交感神经张力的假定指标）在REM睡眠中低于NREM睡眠。
