Hogue C W, Domitrovich P P, Stein P K, Despotis G D, Re L, Schuessler R B, Kleiger R E, Rottman J N
Department of Anesthesiology, Washington University School of Medicine, St Louis, MO 63110, USA.
Circulation. 1998 Aug 4;98(5):429-34. doi: 10.1161/01.cir.98.5.429.
Atrial fibrillation/flutter (AF) is a frequent complication of coronary artery bypass graft surgery (CABG) that leads to increased costs and morbidity. We hypothesized that heart rate variability (HRV), an indicator of cardiac sympathovagal balance, is altered before the onset of postoperative AF. Because nonlinear methods of HRV analysis provide information about heart rate dynamics not evident from usual HRV measures, we also hypothesized that approximate entropy (ApEn), a nonlinear measure of HRV, might have predictive value.
Analysis of HRV was performed in 3 sequential 20-minute intervals preceding the onset of postoperative AF (24 episodes in 18 patients). These data were compared with corresponding intervals in 18 sex- and age-matched postoperative control subjects who did not develop AF. Patients had left ventricular ejection fractions >45% before surgery and were not receiving beta-blockers during ambulatory ECG monitoring after surgery. Logistic regression demonstrated that on the basis of averaged values for the three 20-minute intervals, increased heart rate and decreased ApEn were independently associated with AF. Heart rate dynamics before AF was associated with either lower (n= 19) or higher (n=5) RR interval variation by traditional measures of HRV or quantitative Poincaré analysis, suggesting the possibility of divergent autonomic conditions before AF onset.
In the hour before AF after CABG surgery, higher heart rate and lower heart rate complexity compared with values in control patients were independent predictors of AF. Decreased ApEn occurs in patients with either increased or decreased HRV by traditional measures and may provide a useful tool for risk stratification or investigation of mechanisms.
心房颤动/扑动（AF）是冠状动脉旁路移植术（CABG）常见的并发症，会导致成本增加和发病率上升。我们推测，作为心脏交感神经 - 迷走神经平衡指标的心率变异性（HRV）在术后房颤发作前会发生改变。由于HRV分析的非线性方法能提供常规HRV测量中不明显的心率动态信息，我们还推测，HRV的非线性测量指标近似熵（ApEn）可能具有预测价值。
在术后房颤发作前，以连续3个20分钟的时间间隔对HRV进行分析（18例患者共24次发作）。将这些数据与18例未发生房颤的性别和年龄匹配的术后对照受试者的相应时间间隔进行比较。患者术前左心室射血分数>45%，术后动态心电图监测期间未接受β受体阻滞剂治疗。逻辑回归分析表明，基于三个20分钟时间间隔的平均值，心率增加和ApEn降低与房颤独立相关。房颤发作前的心率动态与传统HRV测量或定量庞加莱分析中较低（n = 19）或较高（n = 5）的RR间期变异性相关，提示房颤发作前可能存在不同的自主神经状态。
在CABG手术后房颤发作前的一小时内，与对照患者相比，较高的心率和较低的心率复杂性是房颤的独立预测因素。传统测量中HRV增加或降低的患者均出现ApEn降低，这可能为风险分层或机制研究提供有用的工具。
