Department of Internal Medicine, Pavia University, Pavia, Italy.
Clin Auton Res. 2010 Dec;20(6):353-61. doi: 10.1007/s10286-010-0079-1. Epub 2010 Aug 12.
Baroreflex sensitivity (BRS) is an important prognostic index in cardiovascular diseases, however, its use is complicated by different methods difficult to compare and standardize, often providing conflicting results. We tested whether the simple ratio of RR interval to systolic blood pressure global variabilities (assessed by standard deviations) is a reliable measure of BRS, by measuring the agreement with six established methods. In addition, we tested whether high-pass filtering of data, by removing slow non-baroreflex-mediated fluctuations, could improve the agreement between different BRS methods.
In 1,409 subjects, we compared 6 established methods (derived by cross-spectral and sequence analysis) and the new method, supine and in response to tilting (1,175 subjects). Data were analyzed after linear detrending, high-pass filtering at 0.025 and 0.05 Hz.
Although all seven methods showed a general agreement, the new method consistently showed the lowest distance from the median of the remaining methods (0.04 ± 0.06 ms/mmHg over 2,584 files, p < 0.05 with respect to the second best method). High-pass filtering improved (p < 0.001) the agreement between methods without reducing the sensitivity to changes induced by tilting. Only the new method could provide estimates in all 2,584 files tested.
The new method intercepts the mean information of all other methods better than any other method, hence providing a simple, easy to standardize (no mathematical constraints) and yet robust and reliable BRS estimate. High-pass filtering markedly improves the agreement of all methods, without loss of sensitivity, and could be routinely used in clinical trials, to provide comparable BRS estimates.
血压反射敏感性（BRS）是心血管疾病的一个重要预后指标，然而，由于不同的方法难以比较和标准化，其应用较为复杂，常常提供相互矛盾的结果。我们通过测试 RR 间期与收缩压整体变异性（通过标准差评估）的简单比值是否是 BRS 的可靠测量指标，来验证这一方法。此外，我们还测试了通过去除慢非血压反射介导的波动的高通滤波是否可以提高不同 BRS 方法之间的一致性。
在 1409 名受试者中，我们比较了 6 种已建立的方法（通过互谱和序列分析得出）和新方法（1175 名受试者为仰卧位，1175 名受试者为倾斜位）。数据在进行线性去趋势后，在 0.025 和 0.05 Hz 处进行高通滤波分析。
尽管所有七种方法都显示出总体一致性，但新方法始终显示出与其余方法中位数距离最小（2584 个文件中为 0.04 ± 0.06 ms/mmHg，与第二好的方法相比，p < 0.05）。高通滤波改善了方法之间的一致性（p < 0.001），而不降低对倾斜诱导变化的敏感性。只有新方法可以在所有测试的 2584 个文件中提供估计值。
新方法比任何其他方法都更好地截获了所有其他方法的平均值信息，因此提供了一种简单、易于标准化（没有数学约束）、但稳健可靠的 BRS 估计方法。高通滤波显著改善了所有方法的一致性，而不损失敏感性，并且可以在临床试验中常规使用，以提供可比的 BRS 估计值。
