Bigger J T, Fleiss J L, Steinman R C, Rolnitzky L M, Schneider W J, Stein P K
Department of Medicine, School of Public Health, Columbia University, New York, NY 10032.
Circulation. 1995 Apr 1;91(7):1936-43. doi: 10.1161/01.cir.91.7.1936.
The purpose of this investigation was to establish normal values of RR variability for middle-aged persons and compare them with values found in patients early and late after myocardial infarction. We hypothesized that presence or absence of coronary heart disease, age, and sex (in this order of importance) are all correlated with RR variability.
To determine normal values for RR variability in middle-aged persons, we recruited a sample of 274 healthy persons 40 to 69 years old. To determine the effect of acute myocardial infarction RR variability, we compared measurements of RR variability made 2 weeks after myocardial infarction (n = 684) with measurements made on age- and sex-matched middle-aged subjects with no history of cardiovascular disease (n = 274). To determine the extent of recovery of RR variability after myocardial infarction, we compared measurements of RR variability made in the group of healthy middle-aged persons with measurements made in 278 patients studied 1 year after myocardial infarction. We performed power spectral analyses on continuous 24-hour ECG recordings to quantify total power, ultralow-frequency (ULF) power, very-low-frequency (VLF) power, low-frequency (LF) power, high-frequency (HF) power, and the ratio of LF to HF (LF/HF) power. Time-domain measures also were calculated. All measures of RR variability were significantly and substantially lower in patients with chronic or subacute coronary heart disease than in healthy subjects. The difference from normal values was much greater 2 weeks after myocardial infarction than 1 year after infarction, but the fractional distribution of total power into its four component bands was similar for the three groups. In healthy subjects, ULF power did not change significantly with age; VLF, LF, and HF power decreased significantly as age increased. Patients with chronic coronary heart disease showed little relation between power spectral measures of RR variability and age. Patients with a recent myocardial infarction showed a strong inverse relation between VLF, LF, and HF power and age and a weak inverse relation between ULF power and age. ULF power best separates the healthy group from either of the two coronary heart disease groups. Differences in RR variability between men and women were small and inconsistent among the three groups.
All measures of RR variability were significantly and substantially higher in healthy subjects than in patients with chronic or subacute coronary heart disease. The difference between healthy middle-aged persons and those with coronary heart disease was much greater 2 weeks after myocardial infarction than 1 year after infarction, but the fractional distribution of total power into its four component bands was similar for the healthy group and the two coronary heart disease groups. Values of RR variability previously reported to predict death in patients with known chronic coronary heart disease are rarely (approximately 1%) found in healthy middle-aged individuals. Thus, when measures of RR variability are used to screen groups of middle-aged persons to identify individuals who have substantial risk of coronary deaths or arrhythmic events, misclassification of healthy middle-aged persons should be rare.
本研究的目的是确定中年人的RR变异性正常值，并将其与心肌梗死后早期和晚期患者的值进行比较。我们假设冠心病的有无、年龄和性别（按此重要性顺序）均与RR变异性相关。
为确定中年人的RR变异性正常值，我们招募了274名40至69岁的健康人作为样本。为确定急性心肌梗死对RR变异性的影响，我们将心肌梗死后2周（n = 684）的RR变异性测量值与年龄和性别匹配且无心血管疾病史的中年受试者（n = 274）的测量值进行比较。为确定心肌梗死后RR变异性的恢复程度，我们将健康中年人群的RR变异性测量值与心肌梗死后1年研究的278例患者的测量值进行比较。我们对连续24小时的心电图记录进行功率谱分析，以量化总功率、超低频（ULF）功率、极低频（VLF）功率、低频（LF）功率、高频（HF）功率以及LF与HF功率之比（LF/HF）。还计算了时域测量值。慢性或亚急性冠心病患者的所有RR变异性测量值均显著低于健康受试者。心肌梗死后2周与梗死后1年相比，与正常值的差异要大得多，但三组总功率在其四个组成频段的分数分布相似。在健康受试者中，ULF功率随年龄无显著变化；VLF、LF和HF功率随年龄增加而显著降低。慢性冠心病患者的RR变异性功率谱测量值与年龄之间关系不大。近期心肌梗死患者的VLF、LF和HF功率与年龄呈强负相关，ULF功率与年龄呈弱负相关。ULF功率最能将健康组与两个冠心病组区分开来。三组中男性和女性之间的RR变异性差异较小且不一致。
健康受试者的所有RR变异性测量值均显著高于慢性或亚急性冠心病患者。健康中年人与冠心病患者之间的差异在心肌梗死后2周比梗死后1年大得多，但健康组和两个冠心病组总功率在其四个组成频段的分数分布相似。先前报道的用于预测已知慢性冠心病患者死亡的RR变异性值在健康中年个体中很少见（约1%）。因此，当使用RR变异性测量来筛查中年人群以识别有冠状动脉死亡或心律失常事件重大风险的个体时，健康中年人的误分类应该很少见。
