Kališnik Jurij Matija, Hrovat Eva, Hrastovec Alenka, Avbelj Viktor, Žibert Janez, Geršak Borut
From the *Department of Cardiovascular Surgery, University Medical Center, Ljubljana, Slovenia; †Department of Cardiac Surgery, Cardiovascular Center, Klinikum Nuernberg, Paracelsus Medical University, Nuremberg, Germany; ‡Department of Anesthesiology and Intensive Care, University Medical Center, Ljubljana, Slovenia; §Department of Communications and Computer Networks, Jožef Stefan Institute, Ljubljana, Slovenia; and ∥Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia.
Innovations (Phila). 2015 Nov-Dec;10(6):398-405. doi: 10.1097/IMI.0000000000000203.
Postoperative atrial fibrillation (POAF) is a frequent complication after heart surgery. It has been shown that cardiac autonomic derangement plays a significant role in the genesis of atrial fibrillation (AF) and that AF might also be promoted by altered repolarization. Thus, the aim of our study was to determine the levels of cardiac autonomic modulation and repolarization properties in patients developing POAF.
Seventy-nine patients scheduled for aortic and/or coronary artery bypass grafting surgery with cardiopulmonary bypass were enrolled prospectively. High-resolution 20-minute electrocardiogram recordings were obtained day before surgery to determine P, PR, QT, and QTc intervals, as well as linear (time and frequency domain) and nonlinear heart rate variability parameters (fractal dimension and detrended fluctuation analysis). QTc interval was calculated using Framingham correction.
Twenty-nine patients developed POAF (AF group), and 50 did not (non-AF group). Groups were similar regarding demographics, surgery type, and perioperative characteristics, except for older age in the AF group. QT and QTc intervals (Framingham) were longer in the AF group [442 (44) vs 422 (28) milliseconds, P = 0.018; and 448 (44) vs 431 (24) milliseconds, P = 0.031 and P = 0.019, respectively]. Time domain heart rate variability parameter PNN50 (percentage of pairs of adjacent NN intervals differing >50 milliseconds) was higher [14% (21%) vs 8% (16%), P = 0.015], and nonlinear parameter detrended fluctuation analysis α2 was lower in the AF group [0.81 (0.21) vs 0.91 (0.20), P = 0.031].
Profound cardiac autonomic derangement, suggestive of parasympathetic excessive modulation, exists preoperatively in patients inclined to POAF after cardiac surgery, whereby parameters PNN50 and α2 differentiated the AF from the non-AF group. Prolonged QTc intervals are associated with an increased risk of POAF.
术后心房颤动（POAF）是心脏手术后常见的并发症。研究表明，心脏自主神经紊乱在心房颤动（AF）的发生中起重要作用，而复极改变也可能促进AF的发生。因此，我们研究的目的是确定发生POAF患者的心脏自主神经调节水平和复极特性。
前瞻性纳入79例行主动脉和/或冠状动脉搭桥手术并使用体外循环的患者。术前一天进行20分钟的高分辨率心电图记录，以确定P、PR、QT和QTc间期，以及线性（时域和频域）和非线性心率变异性参数（分形维数和去趋势波动分析）。QTc间期采用弗雷明汉校正法计算。
29例患者发生POAF（AF组），50例未发生（非AF组）。除AF组年龄较大外，两组在人口统计学、手术类型和围手术期特征方面相似。AF组的QT和QTc间期（弗雷明汉法）更长[分别为442（44）毫秒对422（28）毫秒，P = 0.018；448（44）毫秒对431（24）毫秒，P = 0.031和P = 0.019]。时域心率变异性参数PNN50（相邻NN间期差值>50毫秒的成对百分比）在AF组更高[14%（21%）对8%（16%），P = 0.015]，而非线性参数去趋势波动分析α2在AF组更低[0.81（0.21）对0.91（0.20），P = 0.031]。
心脏手术后易发生POAF的患者术前存在严重的心脏自主神经紊乱，提示副交感神经调节过度，其中参数PNN50和α2可区分AF组和非AF组。QTc间期延长与POAF风险增加相关。
