Yavuz Bunyamin, Duman Umit, Abali Gulcan, Dogan Omer Faruk, Yazicioglu Alkin, Sahiner Levent, Aytemir Kudret, Tokgozoglu Lale, Demircin Metin, Nazli Nasih, Kabakci Giray, Oto Ali
Department of Cardiology, Hacettepe University Faculty of Medicine, Ankara, Turkey.
Cardiology. 2006;106(1):51-5. doi: 10.1159/000092599. Epub 2006 Apr 10.
Imbalance in autonomic nervous system and impaired myocardial repolarization has been shown to increase the risk for arrhythmias in patients with coronary artery disease. This study evaluated the effects of coronary artery bypass grafting (CABG) on heart rate variability and QT interval dynamicity in subjects with coronary artery disease undergoing elective CABG surgery.
The study group consisted of 68 consecutive patients (mean age +/-SD: 61 +/- 9 years) with coronary artery disease who underwent elective CABG. Twenty-four-hour Holter monitoring was performed 2-5 days before cardiac surgery and was repeated 10 days after CABG. ELATEC holter software was used to calculate heart rate variability and QT dynamicity parameters. All subjects had a complete history, laboratory examination and transthoracic echocardiography.
All patients had beta-blocking agent medication pre- and postoperatively. Standard deviation of all NN intervals for a selected time period, square root of the mean of the sum of the squares of differences between adjacent RR intervals, the proportion of differences in successive NN intervals greater than 50 ms, normalized low-frequency power, and normalized high-frequency power were significantly decreased after CABG surgery, whereas low-frequency/high-frequency ratio was significantly increased after CABG. QT/RR slopes over 24 h were significantly increased after CABG surgery for QT end and QT apex (QTapex/RR: 0.16 +/- 0.13 vs. 0.28 +/- 0.19, p < 0.001; QTend/RR: 0.18 +/- 0.13 vs. 0.36 +/- 0.23, p < 0.001).
This prospective study showed for the first time that CABG was associated with a significant worsening of heart rate variability and QT dynamicity parameters in the postoperative period.
自主神经系统失衡和心肌复极受损已被证明会增加冠状动脉疾病患者发生心律失常的风险。本研究评估了冠状动脉旁路移植术（CABG）对接受择期CABG手术的冠状动脉疾病患者心率变异性和QT间期动态性的影响。
研究组由68例连续接受择期CABG的冠状动脉疾病患者组成（平均年龄±标准差：61±9岁）。在心脏手术前2 - 5天进行24小时动态心电图监测，并在CABG术后10天重复进行。使用ELATEC动态心电图软件计算心率变异性和QT动态性参数。所有受试者均有完整的病史、实验室检查和经胸超声心动图检查。
所有患者术前和术后均使用β受体阻滞剂。CABG术后，选定时间段内所有NN间期的标准差、相邻RR间期差值平方和的平均值的平方根、连续NN间期差值大于50 ms的比例、归一化低频功率和归一化高频功率均显著降低，而低频/高频比值在CABG术后显著升高。CABG术后24小时QT末段和QT顶点的QT/RR斜率显著增加（QT顶点/RR：0.16±0.13 vs. 0.28±0.19，p < 0.001；QT末段/RR：0.18±0.13 vs. 0.36±0.23，p < 0.001）。
这项前瞻性研究首次表明，CABG与术后心率变异性和QT动态性参数的显著恶化有关。
