Dimmer C, Tavernier R, Gjorgov N, Van Nooten G, Clement D L, Jordaens L
Department of Cardiology, University Hospital Ghent, Belgium.
Am J Cardiol. 1998 Jul 1;82(1):22-5. doi: 10.1016/s0002-9149(98)00231-8.
Assessment of autonomic tone preceding the onset of atrial fibrillation (AF) after coronary artery bypass grafting (CABG) with heart rate variability was examined in 64 patients scheduled for elective CABG (days 2 to 5). Ninety-six-hour Holter tapes were analyzed in each patient and all events labeled by an experienced technician. The hour preceding AF was divided into 4 quarters (heart rate variability calculated per quarter) and compared with similar time episodes from the group without AF. Twenty-six of 64 patients (40%) had a total of 35 episodes. Only increased age (68+/-5 vs 62+/-9 years) and lower ejection fraction (66+/-16% vs 73+/-8%) were associated with an increased risk for AF. Before onset, a greater number of atrial premature complexes was observed. The standard deviation of all RR intervals (SDNN) showed an increase in the group with AF in the last 15 minutes (significant vs controls and within the AF group). The low-frequency/high-frequency ratio was significantly lower in patients in the first 30 minutes, followed by an increase mainly because the high-frequency spectrum became less important. Thus, initiation of postoperative AF is influenced by autonomic tone variations. A shift in the autonomic balance with a loss of vagal tone and a moderate increase in sympathetic tone are observed before the onset of AF compared with those in controls.
在64例计划进行择期冠状动脉旁路移植术（CABG）（第2至5天）的患者中，通过心率变异性检查了冠状动脉旁路移植术（CABG）后房颤（AF）发作前的自主神经张力。对每位患者的96小时动态心电图磁带进行分析，所有事件均由经验丰富的技术人员标记。房颤发作前的一小时分为4个时段（每个时段计算心率变异性），并与无房颤组的相似时间段进行比较。64例患者中有26例（40%）共发生35次发作。仅年龄增加（68±5岁 vs 62±9岁）和射血分数降低（66±16% vs 73±8%）与房颤风险增加相关。在发作前，观察到更多的房性早搏。所有RR间期的标准差（SDNN）显示房颤组在最后15分钟有所增加（与对照组及房颤组内相比有显著差异）。在最初30分钟内，患者的低频/高频比值显著降低，随后主要由于高频频谱变得不那么重要而增加。因此，术后房颤的发生受自主神经张力变化的影响。与对照组相比，在房颤发作前观察到自主神经平衡发生改变，迷走神经张力丧失，交感神经张力适度增加。
