Chau N P
Service Policlinique, Hôpital Ambroise-Paré 9, Boulogne, France.
Pathol Biol (Paris). 1996 Sep;44(7):592-602.
It has long been known that blood pressure (BP) varies over time. Several methods for monitoring BP over the 24-hour cycle are available. The Oxford intra-arterial method is the most accurate but is too invasive to be suitable for routine use. Noninvasive monitors that measure BP intermittently have gained acceptance in clinical practice. The Finapress device provides noninvasive beat-by-beat BP recordings that are useful for studying BP variability. The reproducibility of successive recordings remains controversial. BP recordings with measurements at intervals of up to 15 minutes yield acceptable results provided the duration of the recording is at least 8-12 hours. BP decreases at night. Whether or not BP varies according to a circadian rhythm is unsettled; if a circadian BP cycle does exist, it may be dependent on the sympathetic nervous system. The method of expression of ambulatory BP monitoring data is not well-standardized: the 24-hour mean, daytime and nighttime means, histograms, and the BP load (based on values greater than an arbitrary norm) are the most widely used parameters in clinical practice. Mathematical methods have been developed for processing outlying data (ten methods have been proposed), identifying low-BP and high-BP periods (the "cumulative sum" and "square wave" methods), and modeling the 24-hours BP profile (a four-harmonic Fourier model seems to be the most appropriate model). Variability can be divided into short-term and long-term variability. Many factors influence the BP curve, including genetic factors, age, physical activity, and to a lesser extent psychosensory factors (the "office effect"). Apart from the difference in BP levels, the appearance of the BP curve is similar in normotensive subjects and in subjects with borderline or established hypertension. Ambulatory BP data suggest that the WHO definitions for hypertension may not be appropriate, and the normal values obtained in the meta-analysis by Staessen are now widely accepted. Ambulatory BP data provide better prognostic information that office BP measurements. In drug trials, use of ambulatory BP monitoring may abolish the placebo effect reduce required sample sizes, and provide new information on the pharmacology of experimental drugs.
长期以来，人们都知道血压（BP）会随时间变化。有几种在24小时周期内监测血压的方法。牛津动脉内监测法最为准确，但侵入性太强，不适合常规使用。间歇性测量血压的非侵入性监测仪已在临床实践中得到认可。Finapress设备可提供非侵入性的逐搏血压记录，这对于研究血压变异性很有用。连续记录的可重复性仍存在争议。只要记录时长至少为8 - 12小时，每隔15分钟测量一次的血压记录就能得出可接受的结果。夜间血压会下降。血压是否按照昼夜节律变化尚无定论；如果昼夜血压周期确实存在，它可能依赖于交感神经系统。动态血压监测数据的表达方法尚未得到很好的标准化：24小时平均值、日间和夜间平均值、直方图以及血压负荷（基于高于任意标准值的值）是临床实践中使用最广泛的参数。已经开发出数学方法来处理异常数据（已提出十种方法）、识别低血压和高血压时段（“累积和”与“方波”方法）以及对24小时血压曲线进行建模（四谐波傅里叶模型似乎是最合适的模型）。变异性可分为短期变异性和长期变异性。许多因素会影响血压曲线，包括遗传因素、年龄、身体活动，以及在较小程度上的心理感觉因素（“诊室效应”）。除了血压水平的差异外，血压曲线的形态在血压正常的受试者以及临界或确诊高血压的受试者中相似。动态血压数据表明，世界卫生组织（WHO）对高血压的定义可能不合适，而斯塔森（Staessen）在荟萃分析中得出的正常值现在已被广泛接受。动态血压数据提供的预后信息比诊室血压测量更好。在药物试验中，使用动态血压监测可能会消除安慰剂效应、减少所需样本量，并提供有关实验药物药理学的新信息。
