Dawson S L, Robinson T G, Youde J H, James M A, Martin A, Weston P, Panerai R, Potter J F
University Department of Medicine for the Elderly, Glenfield Hospital, Leicester, UK.
Clin Auton Res. 1997 Dec;7(6):279-84. doi: 10.1007/BF02267718.
Baroreceptor sensitivity (BRS) is increasingly used as a prognostic indicator in cardiovascular disease. Traditionally it has been measured using invasive techniques with pharmacological manipulation of blood pressure (BP). With the advent of newer methods to measure pulse interval and beat-to-beat changes in BP it is now possible, using sophisticated mathematical modelling techniques, to calculate cardiac BRS non-invasively. However, there are virtually no data on the reproducibility of these newer techniques and what factors may affect the repeatability of these measurements. We studied 39 subjects, aged 22-82 years, with a supine systolic BP range 97-160 mmHg and a diastolic BP range 57-94 mmHg on two occasions between 1 week and 6 months apart. Cardiac BRS was measured by power spectral analysis using Fast Fourier Transformation (FFT), sequence analysis (using up, down and combined sequences) and from phase IV of the Valsalva manoeuvre. There was no significant difference between visits for any of the methods for measuring cardiac BRS. Mean BRS values were similar for FFT (16.7 +/- 11.2 ms/mmHg) and sequence analysis (15.8 +/- 11.4 ms/mmHg); however, results using phase IV of the Valsalva manoeuvre were significantly lower (8.1 +/- 2.9 ms/mmHg, p < 0.0001). The coefficient of variation for the five measures of cardiac BRS varied from 16.8% for Valsalva-derived values to 26.1% for 'down' sequence analysis. However, in ten subjects BRS could not be calculated from the Valsalva manoeuvre. None of the independent variables tested (including age, BP levels and time between testing) significantly influenced the degree of repeatability. In summary, there appears to be little difference between these non-invasive methods in their degree of reproducibility. These techniques would seem suitable for longitudinal studies of changes in cardiac BRS and overcome many of the problems associated with the invasive pharmacological methods.
压力感受器敏感性（BRS）越来越多地被用作心血管疾病的预后指标。传统上，它是通过对血压（BP）进行药理学操作的侵入性技术来测量的。随着测量脉搏间期和逐搏血压变化的新方法的出现，现在使用复杂的数学建模技术，可以无创地计算心脏BRS。然而，关于这些新技术的可重复性以及哪些因素可能影响这些测量的可重复性，几乎没有数据。我们研究了39名年龄在22至82岁之间的受试者，仰卧位收缩压范围为97至160 mmHg，舒张压范围为57至94 mmHg，在相隔1周和6个月的两个时间段进行测量。通过使用快速傅里叶变换（FFT）的功率谱分析、序列分析（使用上升、下降和组合序列）以及瓦尔萨尔瓦动作的第四相来测量心脏BRS。对于任何测量心脏BRS的方法，两次测量之间均无显著差异。FFT（16.7±11.2 ms/mmHg）和序列分析（15.8±11.4 ms/mmHg）的平均BRS值相似；然而，使用瓦尔萨尔瓦动作第四相的结果显著更低（8.1±2.9 ms/mmHg，p<0.0001）。心脏BRS的五种测量方法的变异系数从瓦尔萨尔瓦动作得出的值的16.8%到“下降”序列分析的26.1%不等。然而，在10名受试者中，无法从瓦尔萨尔瓦动作计算出BRS。所测试的任何自变量（包括年龄、血压水平和测试间隔时间）均未显著影响可重复性程度。总之，这些无创方法在可重复性程度上似乎没有太大差异。这些技术似乎适用于心脏BRS变化的纵向研究，并克服了与侵入性药理学方法相关的许多问题。
