Ren LiNa, Fang XinHui, Wang Yongquan, Qi Guoxian
Department of Cardiology, the First Hospital of China Medical University, Shenyang, China.
Ann Noninvasive Electrocardiol. 2011 Jul;16(3):232-8. doi: 10.1111/j.1542-474X.2011.00437.x.
The aim of this study was to investigate the differences in T-wave alternans (TWA) and heart rate variability (HRV) among patients with myocardial infarction with or without diabetes mellitus and the relationship between TWA and HRV.
The study population included 133 patients: 59 patients with myocardial infarction (MI) (group post-MI without diabetes); 40 myocardial infarction with diabetes (group post-MI with diabetes); and 34 controls (group control). Cardiac autonomic neuropathy assessment was made using frequency domain (low-frequency [LF] power, high-frequency [HF] power, LF/HF) and time domain (SDNN, standard deviation of the averaged normal sinus RR intervals for all 5-minute segments [SDANN]) of HRV indexes. Both TWA and HRV were measured on the Holter monitor, and TWA was calculated automatically using the time-domain modified moving average method.
TWA values differed significantly between controls (40 ± 16 μV) and group post-MI with (62 ± 17 μV, P < 0.05) or without (60 ± 15 μV, P < 0.05) diabetes. In addition, group post-MI with diabetes had lower standard deviation of all normal sinus RR intervals (SDNN), standard deviation of the averaged normal sinus RR intervals for all 5-minute segments (SDANN), and HF, indicating depressed vagus nerve activity, and higher LF/HF ratio, indicating elevated sympathetic nerve activity, than controls and group post-MI without diabetes (P < 0.05). TWA correlated with SDNN and SDANN (r = 0.29, 0.31; P < 0.001).
TWA was elevated in patients following myocardial infarction, both in those with or without diabetes. Myocardial infarction patients had a lower time domain, HF, and a higher LF/HF ratio HRV, especially in those with diabetes. The analysis of modified moving agerage (MMA)-based TWA and HRV can be a useful tool for identifying post-myocardial infarction patients at high risk of arrhythmic events.
本研究旨在调查合并或不合并糖尿病的心肌梗死患者的T波交替（TWA）和心率变异性（HRV）差异，以及TWA与HRV之间的关系。
研究人群包括133例患者：59例心肌梗死（MI）患者（无糖尿病的心肌梗死后组）；40例糖尿病合并心肌梗死患者（有糖尿病的心肌梗死后组）；以及34例对照组（对照组）。使用HRV指标的频域（低频[LF]功率、高频[HF]功率、LF/HF）和时域（SDNN，所有5分钟时段平均正常窦性RR间期的标准差[SDANN]）进行心脏自主神经病变评估。TWA和HRV均在动态心电图监测仪上测量，TWA使用时域修正移动平均法自动计算。
对照组（40±16μV）与有糖尿病（62±17μV，P<0.05）或无糖尿病（60±15μV，P<0.05）的心肌梗死后组之间的TWA值有显著差异。此外，与对照组和无糖尿病的心肌梗死后组相比，有糖尿病的心肌梗死后组所有正常窦性RR间期的标准差（SDNN）、所有5分钟时段平均正常窦性RR间期的标准差（SDANN）和HF均较低，表明迷走神经活动受抑制，而LF/HF比值较高，表明交感神经活动增强（P<0.05）。TWA与SDNN和SDANN相关（r=0.29，0.31；P<0.001）。
心肌梗死后患者的TWA升高，无论有无糖尿病。心肌梗死患者的时域、HF较低，LF/HF比值较高，尤其是糖尿病患者。基于修正移动平均（MMA）的TWA和HRV分析可作为识别心肌梗死后心律失常事件高危患者的有用工具。
