Veglio F, Pinna G, Melchio R, Rabbia F, Molino P, Torchio C, Chiandussi L
Department of Internal Medicine, S. Vito Hospital, University of Turin, Italy.
Blood Press. 1993 Sep;2(3):189-96. doi: 10.3109/08037059309077550.
In the present study we estimated the periodic profiles and variance structure of systolic blood pressure, diastolic blood pressure, heart rate and mean arterial pressure by using an autoregressive model of power spectrum, Maximum Entropy Method (MEM) in 8 patients with primary aldosteronism, during long-term therapy with nicardipine slow release. The four blood pressure variables were measured at 30-min intervals, using a noninvasive device (Spacelabs 90202) in 8 hypertensive patients of whom 6 with idiopathic aldosteronism (IHA) and 2 with dexamethasone-suppressible aldosteronism (DSH), before and after 24 weeks of 80 mg nicardipine daily. Blood pressure data were processed by MEM and spectral profiles were obtained. During nicardipine therapy all patients showed a significant decrease of 24-h ambulatory blood pressure values (p < 0.01). Before therapy, spectrum analysis by MEM indicated the presence of high frequency distribution of peaks for SBP, DBP, MAP and HR. The MEM power spectrum showed an increase in amplitude of sharp peaks of systolic, diastolic, MAP and heart rate in all patients after therapy at 24 h corresponding to the circadian rhythm blood pressure. Furthermore, the trend of these variables synchronized themselves in the same period after 24 weeks of nicardipine therapy, with spectral patterns of blood pressure similar to those of normotensive subjects. This chronobiologic approach, by Maximum Entropy Method, may be used as an alternative statistical analysis to search for possible rhythmic behavior of ambulatory blood pressure data before and after pharmacological treatment in secondary hypertensive patients.
在本研究中，我们采用功率谱自回归模型和最大熵方法（MEM），对8例原发性醛固酮增多症患者在长期服用缓释尼卡地平治疗期间的收缩压、舒张压、心率和平均动脉压的周期性变化及方差结构进行了评估。使用无创设备（太空实验室90202），每隔30分钟测量一次这四个血压变量，对象为8例高血压患者，其中6例为特发性醛固酮增多症（IHA），2例为地塞米松可抑制性醛固酮增多症（DSH），在每日服用80毫克尼卡地平24周前后进行测量。通过MEM处理血压数据并获得频谱图。在尼卡地平治疗期间，所有患者24小时动态血压值均显著下降（p < 0.01）。治疗前，通过MEM进行的频谱分析表明，收缩压、舒张压、平均动脉压和心率的峰值存在高频分布。MEM功率谱显示，治疗后24小时所有患者的收缩压、舒张压、平均动脉压和心率的尖峰振幅增加，与昼夜节律血压相对应。此外，在尼卡地平治疗24周后，这些变量的趋势在同一时期同步，血压频谱模式与正常血压受试者相似。这种通过最大熵方法的时间生物学方法，可作为一种替代的统计分析方法，用于寻找继发性高血压患者药物治疗前后动态血压数据可能的节律性变化。
